I just wanted to say that clearly keyservers needed to add this (both verification and specifying the purpose of the key), but clearly they have already done so

I just wanted to say that clearly keyservers needed to add this (both verification and specifying the purpose of the key), but clearly they have already done so. I'm not surprised; these people think a lot more about these sort of things than I do. One possible addition might be that maybe you could specify whether people should use the key to encrypt whenever possible, or only when security is absolutely vital. That's a setting that could pass the decision to encrypt to the sender (if clients support this).