I've ran and hiked a few ultras. I switched to hiking exclusively two years ago when I just couldn't keep my IT band issues under control. Running kills them, hiking doesn't.
I've done a 100k (Coyote 2 Moons, 18k of up) and a 50 miler (Devils Backbone, 11k of up at altitude) 100% hiking, and finished dead mid-pack in both (19 and 14 hours, respectively). So my advice is based on that.
+1 for nutrition planning. DO NOT run a deficit with hydration or food. You can pull out of a bonk, but best not to go there. Sort out nausea issues in training. This might be the best reason to do as long a long run as you can manage, something that you can eat fine for 7 hours might get you heavin' at hour 10.
+1 for specificity. C2M had several big, steep, loose, and hot descents and ascents. I trained in the Grand Canyon, and was able to rock the final climb because of it. This is especially relevant as far as descending goes.
Make an iron-clad promise to yourself that you will finish unless X,Y, or Z happen (injury, etc), then stick to it. Make the mental part non-negotiable so you won't waste energy thinking about quitting when you're suffering like a dog at mile 35.
Making it a goal to run a negative split cane help you from going out too fast.