Ok, my childhood mountain bike that i have for over a decade has finally become unridable... the grip shifter is broken in a unfixable state from an accident. i can ride it as a ss in 6th gear but id rather make it look cleaner.

my questions are:

1) how do i remove the grip shifter completely?
2) are there ss or fixed rear wheels for mountainbikes? or do i have to built my own?
3) the pedal has a very slight play on it and clicks, how do i open up the pedal and fix the play?
4) any tips and or suggestions?

thank you =)