I’m guessing you don’t have any problems with your other plugins deactivated AND a standard theme like 2012. Let me know if that’s incorrect, but the display problems you describe sound more like CSS issues with the theme.
Not being able to save could be a conflict with EM – Google won’t let you load the API twice (I’m not sure why).
You may need to deactivate the maps in EM. Does it have a setting for that? If not, you could try deregistering its script (where it loads the Google API) in your functions.php.
It’s hard for me to just guess what’s wrong, though, without seeing it. If you like send a login and I’ll look.
You can also check if the API is being loaded twice yourself – check the ‘console’ in Firebug or IE developer tools. Google will write a message if its loaded twice.