Have you ever played a mod called Brawl -? It has some neat ideas that we could perhaps use for buffs:
Here are a few examples: While charging d-smash there is a small vacuum effect pulling opponents in(can be escaped by jumping or shielding/rolling)
d-tilt slides her slightly forward, Rollout charges more quickly and(if missed) can be cancelled into a pivot grab, Sing reaches much farther just like in the show. These all improve on her offensive abilities and overall fun to play as and against which is what Nintendo wants in the end.
btw what about adding jab being able to jab-lock again to the list of buffs
?