This I already know. What he was talking about, and what we have been talking about, is opening people up with an assist, not getting a clean hit, meaning it would most likely be heavily scaled and you have a little less options for the high damage series.
As for guard breaking stuff, ambiguious cross up + assist is good. I sometimes do j :h: + assist, zip diagonal down, and then high/low/grab mixup. Pr Rog has good stuff to check out. Hes not particularly strong as a Spencer per say (or maybe he plays differently against high level players), but he has some tricky incoming character stuff.
If you have problems opening people up, command grab more, have an assist that gives you free command grab mixups, and have a combo that can kill a character off a command grab (at least in corner).