well if you dont understabd the digram you shioludnt be jumping into a mod, you should atleast have some soldering skills and knowlage of electronics.
the usb charge is probably the easyest of the ones you said, you just solder a wire from point a to b
the led mod depends on which source of electricity you are using, mst likely the power baord but it could be the mobo.
and the razor nub, you will need to buy a raozr x board from cool-mods to get started with that one
good luck wit ur mods