Adjusting disk brake positions
I hate to say it but this is why it's advisable to go to a bike shop, if you're not sure about setting things up.

You raise a couple of points:


Front disk brake. Regarding your original problem, the rotor should not rub against the pads, period. There should be no contact unless you're actually braking. And when you stop braking, the pads should sit back. I'm not sure where "the wind" has come from, but that sounds like baloney to me - especially if you've taken it to the shop about a rubbing problem. As regards the recent movement - the calliper should be attached to the fork such that movement is not possible. Possibly you didn't tighten things enough, possibly you didn't set them up correctly in the first place. Rain should have no effect.
Front derailleur. It sounds like this just needs to be adjusted, which is straightforward. I see someone has already posted a comment with a link describing how to do this.
Bike looks. Do you really care about this? If it worries you, go ride in some mud. Do this after you get the brake fixed!


I think you should probably have a bike shop look at your front brake, as obviously you need this to work reliably. They'll be able to sort your derailleur too, as I said that's likely trivial. But to be honest I'd be wary of going back to a shop that claims that the rotor rubbing on  the pads is caused by wind - I just don't see how this can be the case.