Hey, congrats!! I think the KH36 is the best 36er you can buy right now… It’s like a night and day difference between my KH36 and my old Nimbus 36.
You’re spot on on the tube - 29er tube is the way to go. I’ve run 29er tubes in my 36 for as long as I’ve been riding 36ers. I’ve got about 3,500 miles on my nightrider tire with cheapo Performance Bike brand 29er tubes (the 48-52c kind) at 60 PSI, and I’ve gotten one flat from riding over a shard of glass that got lucky enough to fit in between the tread chunks on my tire. I’m “leery” of 65, which means I’ll do it if I’m feeling spunky. But whenever I pump it to 65, I always stand back and wish I had an extra arm to cover my ears. I usually stop at 60, but I always go to at least 60, and I’ve never had a problem.
Don’t know anything about the trailmixes; I do know that I am perpetually in love with my MG-1s. The magnesium-with-steel-spindle ones. I don’t want to pay enough to have the titanium spindles. I mostly like them for their grip, though. I’d say that if you feel like your trailmixers are superly grippy, you don’t need to change. Disclaimer: others may or may not disagree. : )
114’s a good overall length; w00t there.
I’d definitely get a handlebar of some sort. A T7 or a Coker bar seem to be the only ready-made ones, but lots of custom ones are out there. If you use a T7, be sure you know someone who welds things, because if you use it hard, it will eventually fatigue and break. Grr. (I’m on my third one now, but w00t, because my first two are welded up and good to go!)
I just shaved my tire, which saved a couple tubes’ worth of weight. Probably got me another half mile an hour on my cruise, which is always welcome. You’re better off riding your tire until the cross-sectional profile gets totally flattened out from wearing off the middle first, then shaving the sides, though. I wouldn’t dream of spending all the time to shave down a completely new nightrider. It took me about five months to wear all the way through the Nightrider tire’s tread in the middle to reveal a flat smooth centerline around the wheel, and once that happened, I shaved the remaining tread off the sides, and I think it did wonders. But it just means that I’m gonna wear the center out further, that much faster… so if you want any life out of your tire, I wouldn’t recommend shaving it until you’ve used up the middle of the tread on the center of the tire… unless, of course, you want to put 90-100mm cranks on it and try to break some ungeared speed records RIGHT away, or something, which you’d probably be better off taking a whack at after getting comfortable enough on your new uni to have used up a good portion of your tire 
