Susan is totally interested although he'd be a terrible teacher and possibly a terrible student depending on who the teacher is. It wouldn't stop him from wanting to hang out with other magic users though who are hopefully not boring.

For what his magic is... Basically Susan's world has magic woven throughout it (creatively called the Weave) and Susan, as a sorcerer, just has an instinctive understanding of how to manipulate it the right way to make it work. This means that it's almost impossible for him to teach, although he would happily show off to others, and of course this is also why he makes mistakes - he knows which 'strings' to pull, but not how to make sure he doesn't accidentally grab the wrong ones too, as a simple explanation.

Which is actually what he would want to learn - he's very happy with his ability of magic, but if someone could help him figure out how to be more... well, precise, with it, and not have so many accidents, that would be great. His brother would appreciate it too.

He does know a couple spells he may be able to teach others though, or explain the theory behind, as he was actually taught these at a magic school - Dancing Lights, Minor Illusion, and (his favorite) Find Familiar.

This of course is all contingent on things happening once he's recovered from, you know. Being imprisoned and then killed.