Since no one else replied yet, I'll give you my thoughts. Installing the pump is straight forward. I would suggest using a relay & the requested wire size. Depending on what your using this truck for will dictate if you need to make any other mods to the tank, hoses, ect. If your making a nice driver (not a race vehicle) & are really doing the electric pump due to not having a mechanical option on the block...then just put it between the sending unit & the metal tube going up the frame. If your going to do some racing, other mods should be made.
As for the regulator, It should be mounted up front somewhat near the carb. Your idea about the "by-pass" on the extra port can work, however a small hole (nitrous jet, carb jet or something similar) is what you'll want to use. The size of the hole really depends on how much "extra" fuel pressure the pump makes...if the hole is too big for the engine's requirements at WOT, you will have a bog/lose fuel pressure. If the pump only makes 7-8 psi, I don't think it will work very well for you.
I made a unit similar to what your describing many years ago, but no regulator was used, just a "T" fitting...I put the inner "jet" of a sandblaster inside the hose on the bottom port of the fitting going back to the tank (in the original feed line) this cut the 15lb. pump down to about 7 1/2 & worked great for several years. Hope this Helps, Lorne