So far I've been doing mainly 2 combos, but other than that I just do random attacks.
1) circle up (which seems to stun nearby enemies for a bit and gets him in the air fast), followed by square down.
2) circle over to freeze, then just run up to them and hit neutral square a bunch of times.
Any good other ones you've been using?
Also, is it possible to freeze someone and then land a level 1 super on them? It doesn't always seem to work for me, and I can't tell if its because I do it too fast and it won't hit while they're frozen or if they have a few frames of invincibility right after becoming unfrozen.
For your last question, I tried doing my Level 1 Super on a frozen opponent and it does work, "sometimes". So it is possible, just hard as hell to pull off since the area of effect is such a small range.