It bothers me that you tag me so often. It makes the use of the tag ineffectual to tag me for any advanced problem that doesn't get answers. There was a point where ALL the threads tagged for me were by you, and it was a hell of a lot of your posts. MOST of the time, you may not have noticed, I just remove the tag. So use it when you need MY help.
If it's a general 'Hey, I need ANY moderator to move/edit/delete something.' you should use
If you KNOW you need ME (and realistically, if you're smart enough to tag if for me, you're smart enough to know where my skills lie), then tag it for me.
Otherwise you're abusing the system.
There's no known plugin to email a submitter when their post is published. http://subscribe2.wordpress.com/ emails a mailing list. You'll have to write this custom code yourself, especially since you're grabbing from a meta field. Hook into 'on publish' to grab that content and, if not blank, email them a message.