Vadinho is much more competent and able than Tony. It provokes the question of "What kind of a super hero movie is it when the SIDEKICK is a better hero than the hero is?" But when you think about it, Vadinho is possibly an angel or god, or at least a guy who has spent his entire life knowing about the mask, the Pumaman, and that he'd have to find him and help him. Tony, meanwhile, is a random American living in Britain with an ostensible connection to academia. Of COURSE Tony doesn't know the first thing about what he's doing! Of course he doesn't have the will-power to resist the mind-control mask. And, of course, he flies like a moron. He's just some random guy who wears a magic belt, not particularly athletic or heroic at all.
Then again, Jane doesn't have any more mental or physical training than Tony does and she manages to (eventually) fight off Kobras' mind control while Tony couldn't.
Puma Man's flight pose looks awkward because he's trying (not very well, admittedly) to emulate a four-legged running/leaping pose, like an actual puma! This is supported by the line one mook gives when explaining to his boss how Tony escaped: "That wan't a man, that was a cat jumping!" It seems if this was meant to be, however, then super jumping would have been a better super power for Puma Man than flight.
Actually he supposedly was jumping rather than flying. Its just the effects are... not up to par.
The movie itself seems confused whether he's jumping or flying. The movie repeatedly calls it "jumping", but he's explicitly shown hovering several times, and once casually walking in mid-air. Maybe he just has infinite Double Jumps.
Tony's reluctance to be the Puma Man early in the film could be seen as a Deconstruction of the standard "wish fulfillment" Super Hero origin story — i.e. the muggle who gains super powers and is eager to start playing around with them (as seen in Spider-Man). Certainly, any normal person would react badly to the news that he's now a murder target because of some super-trait he didn't even know he had. The problem is that Tony's "reluctance" is demonstrated through whiny self-pity which does nothing to endear him to the audience.