I am at about 11k miles on odometer with 10.5k of them being mine since Sept of last year. I suspect I will have about 12k+ miles when my year marker comes around.
1) Pads are still good and with my regen lever I rarely ever use the rear.
2) Rear tire is now at wear marks (BT45's) and the front likely still has 7-9k left on it (if you are ok with scalloping). I plan on changing out the rear here shortly.
Haven't had to replace anything else which wasn't a result of the bike being a former race bike (ie motor bearings / belt / sprockets etc) Granted I have added a lot of mods to the bike
For this same level of yearly miles I would have had to do two 6k maintenance schedules on my ninja 250 and would have only gone 6-8k on the rear tire. Most people who question me about the bike think your savings is in gas ... they are really in maintenance cost / time.
As for bringing a spare belt do you plan on bringing all the tools required to pull your swing-arm as well? Or did you plan on having the bike towed to a shop and having them do it?