How does dk start a uair combo without a grab? the only other way I can think of is through a dair, which is probably even harder to land then a grab.
With an up-air?...
okiyama: I'm fairly sure that the Marth match-up is supposed to be even. DK by no means is shortranged; b-air reaches almost as far as anything Marth has to offer (albeit without the disjointed hitbox), his d-tilt is a good poke with range, his up+B hits Marth from behind and oos, and giant punch is a huge ranged finisher. Marth can combo DK with f-airs, but never finish him as long as DK DIs upward.
A good way to measure the Fox vs DK match-up is to watch the m2k vs Bum videos. Both are excellent players, and Bum manages to give m2k's Fox a run for his money. M2k probably has something else to say about this, but judging by the videos, and the how high he places DK, I'd say he found Bum and DK to be a formidable opponent. Bum plays very passively and as long as m2k attacks, Bum is able to gain an advantage. In the end m2k takes the set by playing less aggressively, falling back on lasers, and forcing DK to approach.
Edit -- Wobbling doesn't make Peach vs ICs even because Peach easily separates Nana. However, wobbling definitely increases ICs chance of winning certain match-ups. At SCC, where wobbling was legal, Wobbles beat Ken (Marth/Luigi), beat HugS (Samus), and took a game from Cort (Peach), placing 5th.