The Airtrain that just does the terminals travels in terminal reverse order so T5 is only the next stop from T7 (no T6) if you end up at T8 you've gone the wrong way and should get off. T4 would be after T5 and T2 after that (no T3).
It's a slight walk from Airtrain to the terminal with moving sidewalks at T5 then down an escalator to departures.
B6 does sell Even More Speed an expedited security lane to get you to TSA document checker faster then you enter the general queue for the scanners.