flick serve problem (and shoe problem)

First of all, I'm 17 and have been playing recreational badminton for several years, although I'm new this year to the club scene, and I hope to start playing competitively at some point. Also, I've been lurking around these forums for a while educating myself; this is my first post.

I played badminton for just two hours tonight, and my feet have been rubbed completely raw and very painful at some parts, making it hard to even walk around, let alone play badminton. I wear just regular socks and sneakers that are tied a little loose. Is it worth my while to buy some kind of court shoes, and where would I go to get them? Is it enough just to tighten my sneakers, or will that make it worse?

Also, I have two questions about the flick serve. Number one, since one of my strong points is digging other players' smashes, I've noticed that I sometimes intentionally feed the shuttle to the receiver (especially if they're weaker) in perfect smash positions, so that they'll smash and I can return it easily, with a drive or some similar thing. Since it's almost instinctive, how can I break this habit before I start facing players who can actually smash well?

The other thing is that my flick serves don't even usually make it that far, even when I am consciously trying (unlike the above situation.) I stand with most of my body still, no part of my arm moves above the elbow, I basically just flick my wrist. What I want to know is, to improve my distance, do I just do wrist strength exercises, or am I missing a fundamental part of the technique?

Thanks for your help!