"I wonder if they actually believe or if it's the new club you MUST belong to in order to get the best parts, etc."
You know, I've been hearing that for almost 20 years, and I really have to wonder about it. The first time I read that claim was in the late 1980s... I was just out of college, IIRC, so it would have been 1987-88-89 or so.
There are a lot of big name stars who are NOT members of Scientology who have gotten and are getting "the best parts, etc." in that time.
As far as I can tell Tom Hanks has absolutely no affiiliation with Scientology, and he's got two Oscars and a couple of blockbuster hits over the past 10 years.
Russell Crowe did think about joining Scientology, but apparently didn't go through with it. From what I understand, that would make him absolutely unemployable in Hollywood, yet he has had a string of GREAT roles and a best actor award.
Same with Denzel Washington. Big role after big role, plus a best actor award.
The opposite side of the coin is Jenna Elfman. Big supporter of Scientology, so you'd expect her to be getting great parts in movies. She's been getting movie roles, but they are uniformly in crappy movies that have limited to no theatrical release.
There are a lot of other Scientology faithful who are also very underemployed, as well.