The first therapist recently told me I was over-boundaried. I have no real idea what she means, I don't think such a thing possible, and I have no idea why she thinks I would care about her opinion on the matter. But I do think it important to recognize that everyone has them. Not just the therapist.
I think reading articles is a good plan - not because they contain absolutes, but because they show how none of those people agree on anything. They give various perspectives to consider. There is no consensus in how to conduct therapy. The closest I have found is the no sex with clients prohibition - and they seem to violate that one with alarming regularity.

Therapy, in how I look at it, (and granted I am not particularly huge on the any sort of relationship idea with a therapist) is the two way street thing is there - but not the same - the therapist gets money from me so that I can tell her things and she stays back. So we both get something -just not the same thing.