Application for maintaining / upgrading multiple WP blogs

</RBHanot, what about WPMU? Might work for your situation.
https://mu.www.ads-software.com/&gt;

I thought that WP MU is only if you use “one domain” and all other blogs will be sub-domain of the main domain. Right?

Can you use separate domains for each blog on WP MU on single installation of WP?

Looks like it might, here is a multiple domain hack. WPMU will let you have more control over individual installs which I think is what you want.
https://mu.www.ads-software.com/forums/topic.php?id=6503&page

You can definitely use WordPress MU over multiple domains. Go to https://mu.www.ads-software.com and search for “domain mapping”.

Virtual Multiblog for WordPress
https://striderweb.com/nerdaphernalia/features/virtual-multiblog/

This gives you _completely separate_ installs of WordPress, but runs them off of a single set of files.

Works over multiple domains or subdomains, and can use same or different databases.

Compatible with most plugins (WP Cache being the only exception I know of.)