Hiya, I use flats as well, Easton Flatboys, good pedals but I've never had decent shoes. Just got a pair of 510 Karvers and the difference is night nad day. Super grip, I was able to get up step-ups that I wasn't able to do previously, the 510s shoe pretty much stuck to the pedal like spds (I ride clipped in on my commuter). Jumps & dropoffs will come, like anything else on a bike it just takes time.
But I've never been able to bunnyhop, the shame.