Uninstalling logistics

My question centers around scenarios for apps that are installed primarily through a given apps option of " Install for all Users" and also for apps that make this decision without asking you.

So you have the same app installed in various user accts and you want to UN-install some of them in a given user acct but not all accts.

(1) Is there any way (looking in the registry etc) to find out if the apps were installed from one main install to all accts OR if it was installed to that one acct only ?

(2) And if the answer to (1) is not cut and dried then I surmise after you un-install (if you must) then you may be faced with re-installing back into the accts you want the app in.

(3) And if the app installs to all without prompting then probably the best one can hope for is to just delete all shortcut references to it in the accts you don't want running the app(s).

Any comments greatly appreciated as I am for the first time dealing with using more than just one acct.

Upon investigating this on my own (novice as I am) it would appear at least one clue that an app was installed for all users would be to look in the "All Users" folder for the apps install evidence. If the Apps functional folders (not necessarily shared folders) are there, then it would seem the app was most likely installed "for all Users" and then an uninstall would probably uninstall it in all users.