For the most part, yes, the Yugo (and maybe the Chinese) that I know of won't work.
Completely agree. I'd grease them up before bagging.Unless you just want spares to give you a warm fuzzy feeling, all you're ever likely to need is a firing pin, an extractor and spring, a disconnector spring and a recoil spring.
Remember that the bolt can't be swapped without checking the headspace and adjusting it if necessary.
In any event, pack whatever parts you buy in vacuum sealed plastic so they don't rust and don't forget to label them. If you don't your grandchildren won't be able to figure out what they are.