Frogga,
Skin breakdowns occur from alot of reasons, but a major one is from poor circulation. If the skin doesn't get enough oxygenated blood, it will start to die, hence the ulcers. A few things you can try would be massages of the upper limbs, very slow, using a good lotion enriched with vitamin E and Aloe. We use a "udder" cream on my mom. It was originally made for cows teets but it works wonders on the human skin! My mom gets terrible skin breakdown from her stroke and this stuff is great. It comes in a jar that is decorated with cow spots and says something about udder cream on it....something like "udderly smooth" or something similar.
Another thing you might try is sheepskin inside your splint. It will keep the splint from rubbing your skin raw.
As for the spasms, have you considered botox injections? I hear they work well. My cousin has been having them done starting from his hands up to his shoulders and for the first time in over 50 years he can finally move his hands and fingers!!
Hope this helps a bit........good luck and keep us posted on how you're doing!

Dianelori