Folk have got to stop looking at this as a fight, a battle. For those who want change to the oppressive regime (dramatic but true) there needs to be clarity that not all battles must be won to win a war. That is what is in front of you, a moral and public spirited war of attrition to save the integrity of your club.
The OSC is not only ineffectual, but also damaging. Their subservience to the club is Quisling like and needs to be abandoned and dismissed as any form of supporter representation.
Take whatever action feels right to you, but listen and share with the HCST. Join it, encourage others, your mam, dad, everyone and anyone to join it. Give them the numbers that give them a voice; their voice can and will bring change for the better. The bigger they are the more allies will come to their (your) aid.
I would encourage them, the Trust, to take the longer view (I think they are) as there will probably be no immediate wins, but probably quite a few tears. Deadlines are those of the club, terms and conditions are those of the club, dignity, truth, patience and strength will belong to the Trust, so join with them and win the war.
The most important thing is that the club hears a very clear declaration of war, no more nice words of appeasement, just straightforward claims of you have gone too far, enough is enough.
A membership scheme could be a good thing, if structured correctly, this one is far from that. Your choice of membership is almost academic, go to games or don't, as the club has railroaded choice. The key thing is to join the Trust and help them in an ongoing war against this hideous scheme, as it won't be won soon.