To the OP, I agree with the above commenters, I would have left long before that as well.
Personally I've had quite a mix of issues using group finder, either tanks specced for DPS and in DPS gear or Sorcs / Operatives specced as DPS and queuing as healers. Anymore for a FP, I will try to stick with it and work through, but if I'm going to PUG an operation, I'll look at the gear specifically on the tanks and healers and decide. If I see something I don't like I will bow out as gracefully as possible, but I don't suffer massive repair bills for anything other than guild and friend related operations. I have rage quit a few times normally using either the "my guild needs something urgently" or "my 3 year old needs something". I've tried not to get on too many ignore lists, though I'm sure that I'm on a few.
Then you are doing something wrong, I am far from a good tank, I do everything I can to avoid it, my gear is DPS, my spec is DPS (Deception) but have tanked LI and story mode EC in said gear and spec only throwing on a shield and tank stance. Its very hard to judge, I recall looking down my nose at some guy with 13k health and crappy gear who rocked the OP we were in, people surprise you, some of the worst players I have ever come across have been the best geared.