Performer 360 Intake help

Hi:

I have a Edelbrock performer that came with a 360 I recently bought. In the pictures below in the lower right side are a couple of what I think are temp sending plugs, and on the left side is what I think is some type of vacuum fitting. In the other pic is the two sending units removed from the intake.
So:
1. Are they temp senders??
2. Does it matter which place I put the new senders that I have yet to purchase?
3. Do I need the vacuum fitting if I am going to a more modern distributer and coil (HEI??)
4. There are 6 or 7 threaded holes that some had brass plugs in them. When I replace the plugs with new ones, how do I seal them in...RTV?? Teflon Tape or something else??

Thanks for your help..FABO is great.