I logged in and visited the userupdate.php page and it appeared correctly for me. I'll need steps to reproduce the issue to debug what is going on.
Can I get a sample verify link that I can use to reproduce the second issue? I'm always going to have to see a problem to fix it, so when reporting issues, please include links and steps so I can see the problem.
You can add a link created date and expiration time limit, but if you haven't done that then it really just means the link is invalid. Again I'd have to see an example. You could add some more logic to determine the exact reason that a link isn't working to further customize the message and say "this account has already been activated" if that is the case.