Is there no middle ground here? Don't do away with parts completely but lessen the diversity of parts needed for a recipe. Eg: no more glue to make a sword or something along those lines.

For Facility and Treatise requirements it sounds like they might have found a middle ground in the current plans. I've seen other people suggest that it sound as if SE has them planned as a bonus instead of necessity. Being a necessity for higher level or rare recipes would be fine too. But since they're used less maybe have the players actually use that forge in LL (animations and whatnot like the npcs do.)

Color changes are good. Requiring specifically colored parts never made any sense at all.

Simplified does not mean better. Parts, treatises and facilities were nice they just needed tweaking like nearly everything else in this game. None of these things have to be scrapped.