Where are the email warnings coming from? I'll guess something like Fantastico? IF this is the case then it'll be quite the chore to get it to stop. As for your blog, freezing it sounds like what you want to do because you're not going to use it. Are you still going to leave comments open?

Anyway I don't think anyone ever brought up the idea of freezing a blog but I'm sure it can be done without too much effort. What I'm thinking is that you need to close as many doors as possible for potential exploits to get in when you're not looking. Could be years from now right? So closing comments on all posts in all blogs is a good beginning. Then deleting the file that actually makes a comment happen. Oh and the syndication feeds might as well go because no one will ever get another update from the blog. I think back then it was a folder called ... aw heck I gotta look. Okay it was xmlsrv and I'm pretty sure you can just delete it without suffering any loss, but I would rename it first just in case. I'm sure you deleted your install folder a long time ago so I won't even mention that detail... Hey do you have more skins than the one you use? If so delete them too because they're just space now.

There's more of course, but hopefully you get the idea. All you want is enough of the core files to keep making your pages - and nothing else.