If I understood @badger correctly, he understands that it's ok, or desirable, to be explicit about what he wants -- but he is too shy/inhibited to express himself directly (something I understand from personal experience). Sharing porn that illustrates what you lust for is one way to deal with that shyness. Another might be to phrase things a little obliquely, along the lines of "I saw a porn scene once that really turned me on. They were [fill in the blank]." Or, a little more directly, "I sometimes find myself fantasizing about [...]."
Absolutely! Some escorts will naturally push you to explore; others hesitate for fear of scaring you or turning you off. Letting them know that you're open to new experiences is important.