WordPress Multisite Multiple child theme

I have a mulisite setup and I am using one theme for multiple sites in it and each site have a custom layout and design. So for that I need to create a child-theme. But I don’t know how to create multiple child theme for each site so I can add customization in each child theme style.css, footer.php, function.php, header.php

Mega WordPress Applications WPMU or otherwise

I’m a small-timer, so I was amazed at this question: Ideal WP multisite server setup for up to 1000 sites?. I know that WordPress is a highly flexible platform, but what types of entities/businesses would need or use this type of setup? In situations like this is there much redundant content? How do you begin designing something like this? Are there lessons in this for the small-timers?

500 error when using virtual host

I’ve got a WordPress MU install in a sub-directory of my webserver. When I point my virtual host at that directory I get my index page but no styling or access to any pages. It’s like it can’t access anything in the sub-directories of my WP root, I get the 500 error. When I check the Apache log it says,