They might as well meet. It might be cool. Actually come to think of it he might qualify for synchronizing (tl;dr here (http://first-darkness.livejournal.com/1426.html) but you don't have to read it if you don't want to bother) but that is up to you. It would mean she wouldn't "accidentally" hurt him in the fray, at any rate XD

I'd say it would depend on how "solid" she makes things. Some things would probably vanish the moment she let go of them, but I'd bet she can make stuff for him to use if she wanted to bother.