1) Yes, but only just by a few degrees, it wont be a huge jump..
2) You could youtube that..
3) Yes most of the coolant have special solution that prevent bacteria and algae growth.
4) Im using the EK supremacy block, and its freaking awesome.. temps are great and it looks good.
5) Again this goes back to your first question, it will only make a 1 or 2 degree change in temps. Its better to go with pull rather than push, so the rad wont get dusty from all that dirt..