If you don't have the need to use different pressures for serving or force carbing, a single regulator is fine. Dual is even better so you can have 1 keg force carbing at a higher psi and serve another at a lower. Check valve distributors are nice, but I have personally used T's with no issues. Sounds like you are on the right path!
As for the gas lines, just make sure you have no leaks and I think you're set.
Keg #1: Empty :(
Keg #2: Empty :(
Kegs 3-5: Empty :(
Ferment #1: Empty :(
Ferment #2: Empty :(
Ferment #3: Empty :(
On Deck: Something....Anything!!!