1) yeah, just connect it straight back up. i believe it comes off the pipe that runs along the back of the block from the waterpump... so no problem there, you seriously wont lose alot. 2) i think its a valve of some sort, and i kept mine... so i would just keep it to be honest! 3)i used some silicone pipe for a few of those and the bigger bore stuff wasnt up to the task. it just flattened out. so you'll defo need reenforced stuff. the smaller ones like to the sensors, the silicone stuff is fine. Rich.