Dropped iPhone 3GS screen lifted-up & WiFi issue, any fix solution?

So my new iPhone 3GS 16gb has a slight issue with weak WiFi signal strength & the screen is 'slightly' lifting-up/out. I had dropped my iPhone 3GS within 7hrs of purchasing it, it died & screen popped out slightly. Fixed the 'dead' iPhone issue but never got to manage the whole flat-screen like factory iPhone 3GS & then I come to find out I now have crappy WiFi signal.

1st ISSUE: WIFI

compared to my iPhone 3G WiFi with full signal & works perfectly, not even far from wireless router, as for my iPhone 3GS WiFi signal is very low at 1bar & cuts off almost every time having to turn WiFi off/on to reconnect. I've already done a Reset Network in settings menu & actual restore from iTunes... It must be due to the drop. What can I do to fix this? WiFi connection does work so I'm sure there's no need for a new purchase.

2nd ISSUE: SCREEN SLIGHTLY OUT/LIFTED

seems to be starting from the top center of sim-tray area, going down the left entire side and ending at the bottom left corner. Pretty sure it wouldn't matter where it's popping out from, as others have this issue, but they & I can't manage to find a fix or solution to this. Well the 'rubber seal' as I'll call it, in between the silver/chrome & screen seems to be off/missing in some areas, so I'm thinking this may have to be the reason for it popping out? No clue or idea really... Anyone got a fix for this?

Please tell me how to fix these 2 issues; making my iPhone flat like as if it were from the factory & get my WiFi working properly. Thanks!