How to put restrictions on android? Is it possible to install android on a tablet and then restrict its use case scenario? What i mean is can i make it so that no apps can be installed (Not even by using an external apk) except the one I pre-install on it?
Something like how normal users/ guest users can't install software on windows without admin password if they don't have the necessary permissions?
You can use Automate app.. It will automatically check if an app is installed and then perform relevant action. You can also set that if package manager is opened, force close it or press home key. You can choose to uninstall it as soon as it's installed if you have  root permissions OR you can delete its files from storage to render it useless OR you can set that the home button is pressed and not responding pop up is shown whenever the app is opened.. LOL
Further you can download AppLock to prevent uninstalling of Automate app or any other app too.
With Automate you can do many more further hacks.
Hope it helps...