Director of Management Company stalling sales

That's an unusual situation but it does happen with older and smaller apartment developments. Has he a Psra licence? Did you know about the management situation before buying? At the Agm the directors and agent have to be approved so thats the time to say you want change. He cannot stop you attending the Agm, as an owner you have a legal right to be there.

It might be useful to speak to other owners and find out who's with you and who's against.

this is correct.

Again, the PRSA might be a good and quick way to go. It is illegal for him to be providing property management services for a fee without a licence.