I did a little experimentation with Parappa, and you can do his down + square move twice and still continue do execute a combo. I got a max of 100 or so AP from one combo.
S, DS, DS, S (repeatedly) = 60 or so AP
S, DS, DS, US (strong), T = 70 or so AP
S, DS, DS, US (strong), C, S x2 = 103 AP (timing is key)
S, DS, DS, US (strong), FC = 90 or so AP
Also, you can use this little technique to pull a Lv. 1 Super off. It should hit, even if they air recover.
EX: DS, DS, Lv. 1 Super
I would post more, but IE is trippin'.
Ps. Almost home so I can test out some of this stuff and a few other combo ideas I came up with =D