Wide gaps have nothing to do with being fixed, unless its a 5 mm gap. If its fixed, it means you cant adjust it, so you can’t unscrew it a bit to make it less responsive. If you do, it will unscrew while spinning.
And yes, its fixed.
Yes, you should get thin lube and string, but thats really all you need. The string color is all a matter of preference, but a bright color is good, so pink is good. White and yellow are too.
PGM is great. I have just v1 without stacks but it rulez. Gap is wide enough for anything. Get many yellow or pink strings (best collours). Thats all, you dont need thin lube, sewing machine oil works the same and it should be cheaper. Also you can wait for one of those new plastics that yyf will relase: Die Nasty, Counter Attack, Pocket change.