Dell 5520 BTX Base PROBLEMS!

Hi I'm a new Dell user and I have been using it for about a month now and I got to say I'm really proud and disappointing at the SAME TIME. Well regardless the good things I want to talk and tell my problems if any Dell user or Dell technicians can solve my problem;

1. As advertised, the GPU used is AMD Radeon 7670M but when I diagnosed it, its INTEL 4000HD which the reason I'm trying to get away with, INTEL graphic is extremely terrible despite the fact many said it is similar to NVIDIA and AMD.
2. The sound problem, when watching movies and sound editing I ALWAYS experience Up-and-Down sound where the sound suddenly high and then low and it happens frequently, this is very annoying.
3. When left idle and the screen turns off, then when I press any key or even move the touch pad, the screen blinks a few minutes then the system when off to restart itself. IT HAPPENS ALL THE TIME!
4. THE MOST ANNOYING AND DISAPPOINTING PROBLEM! would be the INTEGRATED WEBCAM! I use Skype all the time for study and business and for family matters and the WEBCAM always give "CAN'T START WEBCAM. TRY CLOSING OTHER PROGRAM THAT MIGHT BE USING IT" (during Skype session).

Please help me or tell me is this what every Dell user will and have experience? I really thought Dell is the best brand on the market, I guess it was just a gimmick perhaps. Very disappointed user.