Scripts installation

Hello Dear,

I just installed Virtualmin on my VPS. After that, I configured it and added two virtual servers to it. When I add a script to one of my virtual servers, it adds scripts separately to each. Until now, I had Plesk control panel and it using all modules like mailboxes, PHPMyAdmin and etc only once and all users and websites only have their own subscription in them, but here it stores each script separately for every website. I think it's not good because we should store more space and it makes more complexity to manage them.

1. Is there any solution to have a single script for all websites in a home directory not in the public_html of each website?
2. The second problem is that after creating a website, it saves many different files and directories to its public_html directory. can we ignore it?
3. finally, how can we upgrade PHP 7.2 to 7.3 during the administration, not command line? Is it possible or should try with the command line?

Thanks.