First welcome to the board. Second I am glad that this thread is helping on your swap.
Now to try and answer some of your questions.
On your harness if you go aftermarket I would go with a howell. It is the best in my opion, if you want to go all stock there is one in the 73-87 classified section here for sale. (not mine. bigbolck 73 is the one selling it) It is complete. You will want to get a system from a 87-93 truck. It seems to be the most simple to use.
1) Yes I would ground this wire in your case.
2) It shoud be in the t-case. I bought mine from jags that run. They will have every thing you need to make your vss work
3) The knock sensor should be bolted in the center of the bolck. (does not mater what side) I will try to get a pic of mine for ya.
4) The cst should be bolted at the front of a tbi intake.
5) You can just use a switch for this for what you want to do. All it needs is 12volts to the wire.
6)Ecm # is 1227747
7) If it were me I would run a stock tank if it is all possible because of the reliabilty factor. GOOD (not cheap china made crap) In tank pumps just do not give much throbble at all.
8) You will not need a regulator unless you run a higher press fuel pump than stock. You will need to run a 5/16 return line.
I hope this helps you. Any more questoins just ask.
Oh and we like PICS.
