The bike looks excellent. Obviously you know what you're doing here, so I'll just confirm for you that you built a strong bike.
Clothing, surprisingly, looks superb. usually when i see people carrying four ortliebs and then considering a trailer, the clothing list contains 3+ pairs of jeans. Going light with wool clothes is exactly what I've found to be ideal for long-distance touring. Consider bringing one cheap poly top for very hot weather riding, if conditions mandate it. Wiping your brow with wool sucks.
I don't think you need spare cleats. I usually get about 10,000+ miles out of a pair of cleats.
I think your spare tire should be much thinner and lighter. Get the lightest semi-sturdy folding tire you can find. Consider it an "emergency spare" that gets you to the next shop where you can outfit a proper tire. With stout touring tires like you've got, it's unlikely you'll even need the spare, so you might as well minimize weight.
Twelve spokes is way overkill. You planning on building a wheelset? Bring two each and diagnose trueness/tension issues before you pop multiple spokes.
I do suggest a light GPS unit like the Garmin E-Trex 20 for peace of mind on long tours.
A water filter like the Sawyer Squeeze Mini takes up very little weight and allows you to be flexible with your water source.
No need for degreaser, you can always stop in a store and grab some Citrus cleaner once every three months if you think you need it.
I suggest adding some rain mitts. They go a long way in keeping your hands warm. Wet gloves in 32 degree conditions will freeze your fingertips fast. I also suggest bringing some waterproof overshoes for your cycling shoes, or maybe gore-tex socks, although I've found only the former works for a long descent in cold rain. I use snowshoe overshoes from Outdoor Research, they weigh a few ounces and are basically just gaiters with neoprene shoecovers.
The best multitool I ever carried was the Leatherman Crunch. A pair of locking pliers diagnoses so many "What if?" scenarios, it makes my head spin. Stuck parts, worn threads, shredded bolts, etc.
Don't forget a headlamp, bike light, tail light (or two). Reflective tape on your racks is a nice back-up. A reflective vest weighs a couple ounces and can save your life.