I would think at least the threat of compulsory appointment of a strata manager would shake things up. With land grabs, illegal parking (because of use of garage as living space) no records of meetings and improper accounting and banking procedures, I would put money on NCAT making this happen.
The good news is that any such application must include the approval of a strata manager who is prepared to take on the job. That means your friend can go to a strata manager, tell them what he is planning to do and they should help with formulating the application.
I wouldn’t worry about being ostracised. These incompetents are clearly running the show for their own selfish benefit and I wouldn’t want them as friends anyway.
Oh, and a quiet word to the council about the illegal conversion of a garage to living quarters and the extension of private property into common property should stir things up a bit too.
You friend sounds like they need someone to speak for them in negotiations with the other owners. The proposed strata manager may do this but it might mean a visit to an experienced strata lawyer.