I'm not entirely sure why people are getting a UAC prompt, so I'll be looking into that. The .net surprise update was mostly just a miscommunication; I was discussing it with the other dev, he added it in on his merge, and I didn't take any notice of the change. We're fiddling with a way to implement a legacy mode that won't use the new features, but given that the only OS that is limited to .Net 4 is now officially End-of-Lifed, eh. The cool/cheaper things we can do with the new features carry more weight than supporting legacy XP boxes, to my mind. Anyway, next release might have support for .net 4 again. Sorry again for not communicating it to you guys earlier.
Those issues you raised shouldn't be particularly difficult to sort out spellbinder, I'll have them put in to the next release.