I know next to nothing about fixing anything complicated on a bicycle. Have ridden several thousand miles on tour with nothing worse than a broken spoke which I repaired with a temporary fiber spoke.
Get one. Had to call my LBS to find out how to retrue the wheel. BTW, make sure their phone number is stored in your cp. Don't be overly concerned about mechanics. The odds of anything serious breaking are very small. If it did, you probably could't fix it in the field anyway. Your bike shop can talk you through the minor stuff.
Tools I carry:
Leatherman
Allen wrenches
Spoke wrench
Phillips screwdriver
Knife
Cable ties
Duct tape
I would recommend a new chain every couple thousand miles or so. A stretched chain increases wear on the gear teeth, reducing their life span. Clean and oil the chain every 3 or 4 hundred miles, or after heavy rain.
As for gear ratios, the Trucker is stock geared right for most, but your LBS can replace the stock with mountain bike gearing, which is as low as practical. Not too unusual for loaded touring. I just had them installed on my bike and find it just right with 40 pounds of gear aboard. Might find yourself spinning a little high in the flats, but won't have to worry about running out of gear on the climbs.
Be sure and journal your ride. Bet you can write an interesting one.
www.crazyguyonabike.com is a good place for this.