I don't know about the location button. I much doubt that is connected with add-ons. I'll look into it.
But the add-ons - if they are as simple as the Google add-on - I think they can be removed easily from the registry. When you open them in Manage Add-ons, do you see their search address? Here is what I get when I do a find in my registry for "http://www.google.com/search?q=" (that's enough of it to be unique)...
...See that dark number at the top left - {96DD31BE, etc.? After deleting it (which gets rid of the R-pane too), Manage Add-ons now reports...
...Google is gone. Want a talk through? Careful not to willy-nilly do as you please in the registry, though. It can harm the computer.