I think the knurl is unnecessary, smooth will give you finer starting and speed control. The 3' anvil should be OK if you're using bolt on dies. The top of my lower die is at 39.5", but I guess it depends on how tall you are.
Yes, they're used on presses, can be man powered like a flypress. I guess it would work on an air hammer if you can generate enough up force to raise the ram and extract the punch.
On most scroll chucks it doesn't matter which slots the jaws are in as long as they are in the proper sequence. If they're closing evenly they're in sequence. You have 3 combinations of slots they'll go in, check for best sliding fit with scroll out.
Yeah, the green lead seems a little squirrelly. It even looks like it has a larger lug, as grounds often do.
I just don't want to see you smoke anything, and hope all goes well.
I saw that switch at surpluscenter. http://www.surpluscenter.com/pages/Catalog285-152.pdf
It looks like it comes in a couple of different versions, I would double check with a meter between all the leads just to be sure you have what you think you do.
Control wires are easier to to run and safer too, they don't spray oil if they get damaged. It should be easy to incorporate an adjustable limit switch also.
Glad you got it Josh, do you have any photos or drawings of the vise part you could post? Someone out here may have that part and not know what they have.