I LOVE this and I'm proud of you for being brave enough to expose yourself to something new. Trinitarian here... born-in.
I grew up being told they all have different parts right and wrong. Yes, both. Confused yet? Don't be. If you believe a little differently? It's okay... Nobody goes to argue doctrinal differences, they go to hear a gospel. If you don't agree with the gospel you hear, you can find a different one if you'd like from a different denomination... or not.
What happens when he and I have theological differences?
Nothing. You just have theological differences. He or she may welcome your questions/thoughts. We can all learn from someone. If it's a doctrine that rubs sandpaper across your eardrums, you can choose to continue going for the parts you do agree with or you can choose not to go. People will still say hi to you when you go to the grocery store and include you in invitations to gather with them. If you don't show up, they'll either figure you're not into their church (which is fine) or that you were a visitor (which is fine). Your relationship with God is about you and He. Not you, He and every Tom, Dick and Harry sitting next to you. :)
What conflict of interest resolutions will he accept?
I'm not sure I understand this. Are you asking if he'll change his methodologies based on your assertions? If so, uh.. probably not. Most people just switch denominations to ones that fit their models. No questions asked.
Membership requirements.
You are adorable. Uh... how about, "come in peace as often as you like." How about that one?
What path must I exercise to reach God?
Depends on her church on this one. I can assure you, the path will be nominal compared to where you've been.
I would sincerely LOVE to hear your thoughts when you come home.