I actually hate this MB system. There are so many moves (Shazam's torpedo move for example) where you can mash the MB button and the move will only MB if it connects. If the move is blocked, you don't lose the meter. I think that's dumb. I don't like how you can delay the MB on some moves either. I liked MK's system where you had to commit that bar of meter to your EX move. It forced you to be smart with your bar. Factor in that meter gain in Injustice is stupid fast and there's really no reason to be "smart" with your meter (outside of clash, can only happen on lifebar #2). Just MB anything and everything. Fuck it
I remember when IGAU was first announced and people were suggesting a whole bunch of stuff from MK they wanted to see in the game. NRS said "no, this is going to be it's own franchise" and the game is nothing like MK, and all things considered, I think it turned out pretty well. I think the same thing applies here. Keep IGAU and MK separate. No over-the-top transistions (I'm indifferent as to whether or not they bring back the uppercut transitions honestly) and no interactables. I hate how stages play a role in matches.
Just my opinions though
I agree with your other three points.
I don't care about mk9 ex system anymore lol, if mk10 has ex system and makes moves' startup frames really diffenrent, then i'l be fine, if it doesn't change becomes someshit like "20 invincible frames on wakeup" bs like mk9, so fuck it.
The point of losing meter in mb system is like mk9's, to extend the damage/combos, so if you mash the mb button for the moves like shazam's torpedo or aquaman's from the deep, on block the mb parts don't come out, then it's fine and reasonable cuz you spend meter for those moves to extend the combos, if you want more damage, there're other mb moves for you to extend the damage.
sometime i don't like delayed mb moves too, cuz i eat a lot lol, but it's just some kinda trick, so it's fine. it can also prevent you from wasting 1 bar for some random shit. And if you just "mb anything and everything", i don't know how the hell you can play injustice lol. If you don't need to be smart with your meter, then what's the point of clash, so clash is just a stupid thing? lol
But i have to admit meter in mk9 is more important than in injustice.
About stages, like i said, i just want to learn more, not only from characters, but also from stages, it makes the game deeper, and i want to play a deep game, that's all.
btw those transitions, interactables, weapons/stands changing are from mk, i'm a mk fanboy so i want them to be in mk lol. They can do what the hell they want with injustice 2 but give me back those things.