I'm gonna go over some of the things I do to work on my game, then I'll answer your specific questions.
First thing I do every day when I turn the game on, is go in to training mode and brush up on my execution. I work on things that I'm already proficient at doing. My BnB combos in various situations, my lightning run cancel resets. I do this for about 30 minutes and if I seem to be dropping a particular combo for some reason, I might spend an additional 15 minutes working on the muscle memory for that combo.
It's worth mentioning that when I first started playing Raiden, I spent something like 6-8 hours per day in training mode for an entire week learning everything there is to know about the character. I did not even think about going online or doing anything else until I was comfortable with all of his BnB's, his LRC combos, his resets, his frame traps, and some of his common matchups.
It's been 2 1/2 months since I picked him up, which is why I can spend ONLY 30 minutes per day working on these things now. If you haven't put in the lab time with your character, then you have basically skipped the most essential step. It's pointless to play online or offline and try to learn matchups if you don't have a firm grasp on your character already.
After I go through my daily routine with Raiden, I will usually spend a couple of hours learning another character. I try to learn a new character every 3-4 days, but some characters are more complex than others, so it can take up to a week or more. For example, Kung Jin only took me 2 days to learn to a competent level, but Ermac took me over a week.
The reason I learn other characters is so I can be familiar with their moveset and playstyle. So when I get matched up against them with my Raiden, I will have a much deeper understanding of what they are trying to do, and what my options are against them.
There is over 90 variations in the game, so I tend to choose the most common characters first. Scorpion, Sub-Zero, Kung Jin, Mileena, Liu Kang, Kung Lao etc.... I still have more than half the cast that I have barely even looked at!
After learning the basics of a character in training mode. I will spend a few hours playing against the AI on medium. The only purpose of this, is to practice doing the things I've learned on a moving opponent.
Once I feel comfortable with the basic BnB'S and playstyle of a character, I will hop online to play for the rest of the day.
Now here is the most important thing:
I AM NOT TRYING TO WIN GAMES ONLINE.
If your goal is to get wins online, and improve your online record, then you might as well give up now because you're playing for the wrong reasons.
The reason I play online, is to practice specific things that I've worked on in training mode. I'm also there to take notes on other characters, and what I need to work on against them.
For example, the first time I played against a good Scorpion online, I got vortexed to death and I had no idea what to do about it.
I watched the replay and took some notes of what I need to work on, and the next day I learned how to use Inferno Scorpion.
2 months later, if I play against an Inferno Scorpion, I will punish every teleport, every slide. I will fuzzy guard every reset. I will stay out of the air and not contest his Ji3. I know the range of his D4 and I have a good idea of what he wants to do at every moment of the match. I know the frames and properties of all his strings, and I know when and how I should poke out or armor out if he's pressuring me.
My goal when playing online is to practice these things that I've learned about Scorpion, and continue to take notes on the matchup, so I can practice more things against him in the lab. Right now I'm working on reacting to his 21xMinion strings, so I can interrupt him on reaction with Raiden's F1.
Sometimes I will spend time "exploring" my character. I will read the Raiden forums, watch videos of Dizzy or Digit, and try to implement parts of their game into my own, or come up with my own ideas. Right now I'm working on converting off of my EXDB2 anti-air. I'm also working on counter-poking with B12 LRC and confirming into a combo or a reset. I might spend a few hours online trying to specifically land these things.
Every Sunday, I go to a local venue in my city, to play offline with my local scene. I am lucky enough to live in a city where there is a steady group of guys to play with. If you haven't explored the local offline options in your city, I suggest you do so ASAP. Check out the matchmaking forums on this site, make a post on the MKX Reddit, look for FGC related facebook pages in your city. Do whatever you can to find people to play with offline because it helps immensely.
We are now also getting together for casuals on Mondays, so that's 2 days a week where I play offline for several hours.
I also try to enter and train for as many tournaments as I can. We've only had 1 in Calgary so far, but there is another one coming up on Aug 1st, and then another on Aug 24th. Then I'll be training for Canada Cup in October. Training for these tournaments gives me motivation to keep leveling up my game, and studying matchups.
Another very important part of my process, is finding good players online with good connections, and adding them to my friends list so I can play extended sets with them. I use a capture card to record these sets, and then I study them and write extensive notes on the matchup. Sometimes while watching these replays, I pick up on very bad habits of mine, or missed opportunities, and I go into the lab and work on those things specifically, then go online and work on them some more.
I also spend a lot of time reading this forum, the MKX reddit, and watching streams. (Pretty much only Tom's stream but sometimes Wonderchef.)
playing online doesn't help you get better
Playing online helps you get better at.... playing online. For some people, this is all that matters.
Personally, as I've said, I believe that playing online can be helpful as long as you go into it with the right mindset. Be aware that the lag has a massive effect on the effectiveness of certain strategies, so if you think you're godlike just because you spam D3 all day and jump around like a moron, you're gonna be in for a huge surprise if you play someone offline and they anti-air you consistently, and counter poke your D3's every time.
I spend around 20% of my time playing online, and I'm usually just working on specific things, as opposed to trying to win games.
How do you practice your moves? Do you drill one a session and go online to practice that move?
Aside from my daily routine, yes, I do this a lot. I will learn a new combo, frame trap, reset, knockdown setup.. whatever, practice it for 15-30 minutes, and then go online and try to land it in a match.
Do you train vs a standing AI? Or Very Hard AI?
After I feel comfortable against the standing AI, I will spend maybe an hour doing ladders on medium difficulty, just to get a feel for doing things on a moving opponent. Playing on hard/very hard is pointless IMO unless you're specifically working on blocking/punishing against a certain character.
When it comes to inputting combos, especially online, is it slow or deliberate or do you attempt to input them as quickly as possible?
I'm not entirely sure what you're asking here. My inputs are definitely ALWAYS deliberate. I never mash buttons frantically if that's what you mean. The only thing that changes online is the input delay. So I'm inputting my combos exactly the same as I do in training mode, I'm just doing them earlier.
For example, Raiden's B2 B2 in the corner, in training mode I have to wait until his arm extends all the way down before I press the second B2. But online, I can press the second B2 when his arm is at the "4 o'clock" position, because of the input delay. If the lag is really bad, I'll have to press it even earlier than that.
The only thing that's changing is the visual cues that I use for timing.
I do the exact same combos online, as I do offline. I just have to learn 2 different sets of timings.
How do you deal with pressure? Do you wait for the combo to be dropped or is there a read to know when its safe to poke out?
This is entirely dependent on the character you're facing, and this is exactly why I continue to learn new characters.
For example I have recently learned that I can armor through Ermac's F21D2 string. Previously, I would block this entire string and then he would be at neutral frames, and most likely counter hit me with a D3 into a mixup. Now that I'm aware of his frames, I armor though this string on reaction every time. And if he catches onto it and starts doing F212, my option select will cause me to still block the 3rd hit even though I stopped blocking for a moment to do my reversal. If he tries to do F21 and bait my reversal, I will make a read that he's baiting, and I know that he's -14 after F21 so I will full combo punish.
This type of stuff just boils down to knowledge, which I am constantly accumulating. Probably the most time consuming part of the game.
How do you punish? Do you start inputting it the moment the last hit lands? Or is there a way in which I can let off block a split second early and start punishing?
It depends what you are punishing.
If Kenshi does EX Rising Karma at max distance, the only thing I can punish with is a reversal BF3.
Since I'm using a reversal special, I can input this about 6-8 frames before I come out of blockstun, and the move will come out on the first available frame. (Actually it comes out 1 frame faster since it's a reversal.)
If he's in the corner, and does EX Rising Karma right in my face, then I will have to wait until I am completely out of blockstun. I know from experience that I will come out of blockstun when the blue spirit guy reaches the top of the screen and starts to fade away.
Since I have practiced punishing that move in the corner in training mode, I have no problem recognizing the correct timing for when I need to press my standing 2 to get a full punish.
Punishing, like combos, frame traps, setups and pretty much anything else in the game, requires practice.
If you haven't spent time in the lab learning to punish something, then don't be surprised if you hop into a match and cannot punish it consistently.
I realize this post is absurdly long, but you did ask for a detailed response
Hope it helps.
above average ferra/torr and a mediocre level Kano, Jax, Jason, and trash level Mileena, and will add predator to that trash level list this Saturday! 
them i get bodied because ferra/torr can't play a zoning game
