Fastest moves in the game are 6 frames. F2 is 8 frames and leads to full combos from mid-range. Your speed complaint is invalid.
Getting In;
- Walk, block. Basic but spectacularly under-appreciated. Very useful against heavy zoning match-ups.
- Walk or dash into max F2 range. From there you don't need to do anything too risky. Your F2 goes roughly the same distance your dash does. Whiff punish, or just hit their block with F23 xx Breath and you're in.
- DF+3 knocks opponents down at distance and gets you in FREE. Don't spam it, it is very unsafe.
- Heat Zap Heat Zap Heat Zap Heat Zap. If they block it, free dash. If they crouch it, free dash (usually). This move is so good for the neutral game.
- Heat Vision [MB], if it hits, dash in. Don't worry if you're still not that close. You're gradually pushing them to the corner and that's what matters.
Keeping up Pressure;
- Grab > Block. If they block excessively, grab them. Once they start teching, you can punish that by using B3 / walk back F23. Condition them to expect throws and they will start mashing tech or random buttons, which provides you with more openings.
- Use B1, it has deceptive range. Especially if you walk back and do it.
- Use Heat Zap in blockstrings (does 6% in chip and +19 on block). Most players will start ducking in anticipation, because you've conditioned them to look for a particular blockstring ender. Commence using overheads / throws.
- Use F23 xx Breath to push them into the corner. If you notice them stand blocking your annoyingly safe pressure, use F2D1 to open them up for a full combo (SO much damage in the corner with this)
There is so much more that I could say, but really you just have to think outside the box. You have to trick your opponent to get hits, that's the bottom line.
edit: I think I'm going to write a mini supplementary guide thingy to go with SaitsuYesHadou's.