FX 6100 is also not that bad CPU. I guess your motherboard is holding you back. Upgrade to a 990FX or so first. However, if that's the case, I would suggest you to go Intel route instead but again it will cost you.
Keyboard drivers are inbuilt and system should pick up keyboard even before booting OS. If your keyboard is not working during system startup, there must be something wrong with keyboard. Try a alternate keyboard if available.
Yep, 850W is apt for this system configuration. However, if you plan on SLI system later, its better to go atleast 1000W with GTX 980.
Mobo seems great too. Chk: http://www.bit-tech.net/hardware/2014/09/09/x99-motherboard-group-test-asrock-asus-e/5
This error must be given by monitor display. There is nothing wrong with it. It generally happens if the monitor is not displaying its optimal resolution. You may right click on desktop, go to properties and change resolution to 1366x768 from there.
Check in device manager under imaging devices if it is listed there. Try downloading and installing installing Dell webcam central from dell support site and see if it helps. otherwise, webcam hardware might have malfunctioned and it might be faulty.
Usually this happens if battery is unable to give appropriate backup and degraded beyond 30% capacity. It will not be able to hold charge for longer durations and will give less battery backup.
Try visiting Nvidia website and download/install latest graphics driver for your system. The old graphics driver are probably corrupt and a cause of this issue. If it doesn't work, try completely removing the old nvidia drivers first and then install latest drivers.