This answer covers some important points based on an assessment of the user's ability to learn. This answer is intended as a supplement to that one.

It sounds like you still consider the user to be valuable, aside from this disruptive behavior. That is, you'd rather have him than not. It's important to note that if that ever stops being true, you need to step back and re-assess. If a user's net contribution shifts too far to the negative, you might need to restrict his access despite the positive parts. (Just make sure you're following your site's rules in that case.)

The problem you describe is that he, basically, sprinkles crappy edits (and comments, which I'll come back to) all over your site and you, the moderator(s), have to clean that up. But if he can edit, then so can other users -- and the only way to keep up with the scale of his edits is to get other users to help. This needn't, and shouldn't, be your job as a moderator; you have other things to worry about, things that only moderators can do, and that's where you need to focus. You can't do all the site maintenance yourself or you'll burn out. You need to push maintenance that other users can do to those users.

On Stack Exchange, an edit produces two effects: it bumps the post to the front page, and it leaves a record in the user's activity log. Publicly you don't want to focus on him (you've said he doesn't take criticism well), but you can ask the community to pay more attention to edits in general. Review your editing guidelines, e.g. that style-preference edits aren't accepted and what your definition of "too minor" is. Ask people to improve or roll back edits that hit the front page that don't comply with those guidelines. Make it abundantly clear that anybody with the privilege is welcome to edit, even if that means editing a previous edit.

Privately, you can check in on his edits to see if either they are improving or the community is handling them. Don't use his edit log as a jumping-off point for you to fix all the things; that'll suck you down a rat hole. I wouldn't even look at the most-recent ones, say the current and previous days. Review the stuff that the community has had time to deal with. If they're dealing with it, great! Drop an encouraging comment on your meta or in chat thanking people for the good work (speaking generally, of course). If they're not dealing with it, try again to engage them (meta, chat).

As for comments, it sounds like you might need to be more ruthless. If his -- and anybody else's -- comments are not serving their purpose, if they're non-constructive or tangential or brewing arguments -- then nuke them. He may complain to you about that, but if he's harming the mood of the community or driving away other users, that has to take priority.

This answer covers some important points based on an assessment of the user's ability to learn. This answer is intended as a supplement to that one.

It sounds like you still consider the user to be valuable, aside from this disruptive behavior. That is, you'd rather have him than not. It's important to note that if that ever stops being true, you need to step back and re-assess. If a user's net contribution shifts too far to the negative, you might need to restrict his access despite the positive parts. (Just make sure you're following your site's rules in that case.)

The problem you describe is that he, basically, sprinkles crappy edits (and comments, which I'll come back to) all over your site and you, the moderator(s), have to clean that up. But if he can edit, then so can other users -- and the only way to keep up with the scale of his edits is to get other users to help. This needn't, and shouldn't, be your job as a moderator; you have other things to worry about, things that only moderators can do, and that's where you need to focus. You can't do all the site maintenance yourself or you'll burn out. You need to push maintenance that other users can do to those users.

On Stack Exchange, an edit produces two effects: it bumps the post to the front page, and it leaves a record in the user's activity log. Publicly you don't want to focus on him (you've said he doesn't take criticism well), but you can ask the community to pay more attention to edits in general. Review your editing guidelines, e.g. that style-preference edits aren't accepted and what your definition of "too minor" is. Ask people to improve or roll back edits that hit the front page that don't comply with those guidelines. Make it abundantly clear that anybody with the privilege is welcome to edit, even if that means editing a previous edit.

Privately, you can check in on his edits to see if either they are improving or the community is handling them. Don't use his edit log as a jumping-off point for you to fix all the things; that'll suck you down a rat hole. I wouldn't even look at the most-recent ones, say the current and previous days. Review the stuff that the community has had time to deal with. If they're dealing with it, great! Drop an encouraging comment on your meta or in chat thanking people for the good work (speaking generally, of course). If they're not dealing with it, try again to engage them (meta, chat).

As for comments, it sounds like you might need to be more ruthless. If his -- and anybody else's -- comments are not serving their purpose, if they're non-constructive or tangential or brewing arguments -- then nuke them. He may complain to you about that, but if he's harming the mood of the community or driving away other users, that has to take priority.