Carburetor Cleaning & Tuning 101
#132
Is your air box clean? if your air box has green stuff in it, id be worried. Other wise just clean those carbs really well.
#134
#137
#138
#139
Do you have a jet kit installed? You can't do much tweaking otherwise. You could shim your needles up a tiny bit and turn out your idle screws. However I doubt you will need to do any tweaking for just a pipe. Ride it first and find out.
#140
There are 2 holes on your petcock. one fat one (fuel) and one smaller one (vacuum). The 2 lines that come from the bottom of the gas tank aren't a big deal. They just lead to the ground.