I know it is nerve-wracking even if you have a vet you trust. Sounds like you have a handle on all of the basics.
All of my rabbits over the years have been altered and they are wonderful bunnies full of personality. You may see less aggression (IF you had any of that), but even my Vivian who has been spayed for 5 years now still has her spunky personality which includes her funny grunts and huffs. It's just part of who she is. :0 ) So though you may see some mellowing in some characteristics (territorial etc), your bunny is young and still full of energy and I doubt that will change.
Sounds like you have a handle on what to expect tomorrow but here is a good resource for pre-post surgery care. Some of which you may already know -- doesn't hurt to review.
The other thing is to ask your vet about pain meds. Some vets will give enough at the office to last 24 hours and so they don't send you home with any, and some will give you a couple of days worth to make your bunny more comfortable during the recovery process. So, be sure to check what they do for post-surgery pain management .
One of our members (can never remember who!) gave a great tip on how to check the incision without stressing your bunny. IF you have a feisty gal who is not fond of being picked up this is really helpful. Check the insicision with a hand mirror while you are giving your bunny a treat -- basically have your bunny stand up to get the treat, and you can either get a good look yourself with your own two eyes or if that doesn't work, use a hand mirror to get a better look.
The other thing is --- just try to relax and imagine only the good stuff while this is all going on, to prevent yourself from worrying to much. It will be okay. 
Sending easy surgery and fast healing vibes!
Keep us updated.