Need to know if I can adjust water temp at the faucet. Seems like it doesn't get hot enough and instructions that came with faucet are very poor. Also why does water come out of shower pipe when lever on spout is not lifted, spout not even connected yet.

Depends what type/brand/type your faucet is and how old it is. Newer, single handle faucets have anti-scald ring installed behind the handle. In this case, you would remove handle, remove the ring, reinstall handle - and you get more hot water.