BuildTAK is especially made for stuff like ABS or PET (both materials can warp with other adhesives), so there won’t be an issue with that. The fact that i told in “c)” should just advise you to not stack adhesives like kapton tape, BuildTAK, blue painters tape and more on your heated bed, at some point your bed will just be too uneven and will have issues with heat transfer, but just one layer of buildTAK on your heated glass plate will be fine.
I don’t think, that BulidTAK is made to be reapplied, but you can test it out of course, as long as the bottom side is still sticky enough, so that it will hold on to your glass bed, everything should be OK. I would prefer a new sheet of BuildTAK, but due to BuildTAK being expensive, I guess it would be worth it to find out, if you can apply BuildTAK multiple times.
BuildTAK is made to provide a good printing surface for ALL materials, so don’t be afraid when switching from PLA to ABS etc., BuildTAK will handle the adhesion part, if the bed is leveled correctly.
However you still have to check for a perfectly clean (unclogged) nozzle, as residue from other materials can cause issues during the print. For example some left over PLA can “burn” down to small black particles in your hotend, if you print ABS (at 230C or similar), those particles are very difficult to remove and will stop your ABS from extruding smoothly.
PS: if you use 1,75mm filament you can try to push an 1,5mm allen key down the hotend, to push out all left over material, this is no perfect, yet very good method to clean out the hotend, otherwise use cleaning filament, if you have to change the material very often.
Cheers,
Marius Breuer