How can we shine a light on this? Get them to step down maybe.
You have a number of options and it depends how dirty you’re prepared for your hands to get.
In the case of the unapproved renovation, report it to the council planning department. If they refuse to do anything, report them to the Local Council Ombudsman.
In the case of the self-serving chairman, gather your evidence, and as much supoort as you can get from other owners, and begin action at Fair Trading and NCAT under Section 238 to have the chairman either removed from the chair or from the committee entirely. They might jump before they are pushed if there is too much dirty laundry to be aired.
Regarding the pliant strata manager, you could apply for the compulsory appointment of a strata manager to take over the running of the strata scheme under Section 237. Be sure you have a good strata manager ready to work with you if you go down this tricky route.