As for replacing the webcam, you're going to have a tough time finding something that not only matches the view hole, but mounting as well. You'd have to find a camera with the EXACT size as the original then manufacture a custom bracket for it, making sure the total depth doesn't cause the lid to bulge and keep you from closing the laptop. As for the LED - it might be possible to find an inverter and jerryrig it to work but the display that originally came with it is pretty good and the cost/benefit ratio is pretty sad.
As for ram, you won't get more than 8gb because the board is hardwired to only accept that amount. Hardmod is impossible here as it would require changing lanes and the way the board receives/sends information. The MCM (memory control module) is soldered onto the board, directly into the memory lanes, upgrading the MCM would require adding lanes. Fidling with the OS or Bios will not give you any more capabilities than what the MCM allows.
With respect to the GPU - THEORETICALLY you can do a reflow in your oven which is not only EXTREMELY difficult but it can also damage your board considerably. The other option is directional reflow with a reflow rig. You would also have to reball. Even at that, you may ONLY be able to upgrade to a GPU that was originally offered with your board. The size, lanes, spd and other things must match. Even at that, it's not guaranteed the mod will work.
Overclocking requires a PLL mod - this means soldering two pins together and creating leads from two other pins; soldering them somewhere else on the board. A simple pin mod on the CPU will not work. SetFSB by itself won't work either because the FX is TME locked (timelocked). Having said such, after the modding, you might want to do some more modding to increase cooling. The laptop NB is cooled stock, however the SB is not and you will probably want to take care of that - it may require custom brackets, holes, case opening, etc.
As for temps, you might be able to use the spacing between the MB and the lower casing to stuff a TRM (temperature read module) with leads into a small LCD - cut a hole in the palm rest and install your readout. Other than that, you can get software to give you a nice "always on top" readout. Temps are hardcoded into the chips so the bios can read it in the event of critical shutdown.
Hope this clears a few things up and answers your questions.