I agree with most of what the T wrote to you and you posted here, and yes, she writes very clearly and it makes a lot of sense. But not all Ts work transferentially, so there might be other reasons for their boundaries. My T is pretty open, and her website used to list her kids and what sex they were, and her hobbies. She answers most of my questions but she also makes it clear that therapy is about me, and she doesn't want to spend much time talking about herself.

Regardless of knowing some things about her, I still have experienced transference because I always wanted her to be someone she can't be to me. I also just had the incident of getting triggered by her talking on her phone after my session. So, transference can happen even when a T does disclose things about themselves. I would have a hard time seeing a T who was a "blank slate" and didn't tell me anything about herself, but I wouldn't like one who told me too much, either. I think there can be a middle ground, and therapy can still be productive.