Baby steps, in Cinnamon 1.1.4. the search will filter system settings as well (e.g. if you type "mouse" the mouse settings in system settings will appear), hopefully not too long from now it will zeitgeist integration so you can filter recently used files and folders - but, searching repositories? Did the old Mint Menu do that? I don't remember ever seeing an uninstalled repo package in mint menu. There's a gnome shell extension that does exactly that, I'll try and port it to Cinnamon at some port.
Thank you for this thread. That’s all I can say. You most definitely have made this forum into something special. You clearly know what you are doing, you’ve covered so many bases. Thanks!