You don't need to purchase any trail stickers for this route do you?
No stickers needed. The trail is designed to avoid any counties that require stickers for plated bikes.
I've done the trail twice, 2015 and 2016. I'd recommend doing the whole thing if at all possible. Some of the most fun sections are the Iowa section on the SouthWest part of the trail and around the Clam Lake, WI area. Those sections can be wet, so try and pick a day when it hasn't rained in a while if at all possible.
It's a 3 day ride going at a normal pace. I did it both times on Shinko 700 tires. 804/805s will be excellent.
If you have an Android phone, I'd recommend using the GPX Viewer app: https://play.google.com/store/apps/deta ... ewer&hl=en
I used it last time and it was amazing. Very easy to follow the trail. Best part is it's free.
I've never gone moto-camping, so if you can give me any tips or suggest some posts to read that would be awesome.
Try and keep things light. Don't overpack. There are enough towns on the way to at least eat lunch every day in town.
Bring all the tools you need for general maintenance. Bring spare tubes, patch kits, and Tire Slime, as well as a decent pump (manual or electric). You'll want to air down your tires when you get to gravel. If you want, I can email you an item list that I put together that's served me pretty well. PM me your email and I can send it to you.
Your side cases should be fine. I don't know if it's worth buying new ones if the ones you have work well enough. One way to save some weight would be to share a tent with your friend, if that's a possibility. If you're creative, you can think of others.
It's a beautiful trail. I think you'll really enjoy it.