This is what I think. For example, my t has said he'd be interested to read a diary from when I was a kid. I could give it to him but it doesn't feel like the right thing to do yet. I can't trust him to respect it/me (at least yet) so I don't think giving it to him now would be the right thing to do. I want him to understand me better before I give him a chance to misinterpret something as personal as my diary.

I don't think there's anything wrong with it as far as your t is concerned if you share everything. It's your t's job and they're not going to be hurt or think it's inappropriate toward them if you share things.

I do remember hearing that if a client spills their guts right away, it might make the therapist wonder about the client's boundaries or self confidence. But it doesn't mean the client did something bad, just that the therapist might be able to help if that causes problems for the client in real life.