Sure, it's a good idea to lube everything. But the window moves vertically, and spraying that vertical track near that's near the edge of the door will keep everything moving along nicely. And it works it's way down into the horizontal track.
My mechanic (RobertP) swears by the Honda stuff. I didn't go to the trouble of getting that brand, but I will if I find myself at the Honda dealer some day I will get some.
The vapor barrier protects the interior panel from moisture.
I recommended rebuilding the Ford one's. They fit exactly like they should. But you already have an aftermarket one, I guess they're worth rebuilding.
97 T-Bird LX 4.6 - 68k miles
94 Supra TT Auto - street/strip car
04 Crown Vic Police Interceptor - Brenda's car
95 T-Bird LX 4.6 - fully optioned, owned 15 years
96 Cougar XR-7 4.6- Brenda's car, owned 11 years
88 T-Bird 3.8 - first T-Bird, owned 5 years