Adding a few points~
You can get grabbed out of Super Armor and most grabs have invincibility frames (assuming they hit).
Every class has a launching skill given to them when you start the game, initially set to 'Z'. At level 15, you get the cancel for the skill which adds a whole new world of comboability. However, in pvp mostly, after comboing for too long, the enemy will fast fall. That's mostly to prevent infinites since they're not that hard to do.
PvP has different stats for skills as well. That's to prevent some skills from being too overpowered (though some of them still are anyways).