I'm so sorry! And I completely understand your nervousness.
(I'm going for a partial knee replacement in April, but I have to sign off on them converting to a total if they think that's best when they're in there. That's the worst part; going under and not knowing what you'll wake up with. I have control issues.
Here's some good news: I've had two knee surgeries on my left knee, one a classic clean up arthroscopy and meniscotomy, one a lateral release. Recovery was fairly easy on both and I was back riding very quickly. I'm also considerabley older and less fit than you.
As scary as the not knowing what you'll wake up with thing is, consider the alternative -- would you want your surgeon to go in with a plan written in stone; and not be willing to deviate from it no matter what he found? Really, sounds like your surgeon is careful, thoughtful and considering all the options.
Individually, none of those things sound too bad. 3 - 5 of them together might be less fun, but focus on the potential - you could have less pain and more function very soon.
Just be prepared to follow the post ops suggestions and physical therapy to the letter.
Oh, and one more weird suggestion. Have someone with you to take notes and ask questions when the surgeon comes to talk to you post op - they're usually very chatty and offer information they might not in a more formal setting, and the patient isn't focused enough to take notes and ask questions.
Good luck! I'll have my fingers crossed for you!