Re: the above. SPL makes some replacement bushings for 1+2 already:
SPL PRO SUSPENSION | 09+ Nissan 370Z Z34 . #3 is part of the shock assembly, but I guess you can press those out and replace as well?
#4: The mfg doesn't intend the lower ball joint to be repair/replaceable, they have you replace the whole lower arm (which is actually pretty cheap), but I don't know if maybe the aftermarket has some way of replacing that ball joint or not. Looks unlikely to me though (I've replaced my lower arms already once w/ new OEM, have my old ones sitting in the garage to look at).