Multiple but separate WP updates

Hopefully someone can follow my thought process here.

As far as I know, WPMU allows to update multiple blogs as long as all those blogs reside under “sub domains” of your main site

I was told that WPMU Dev, might be what I’m looking for but can’t find any info.

So here we go:
Finally have a Custom wordpress template in the format that I want, columns where I want them, widgetables where they need to be etc.

Multi Part question.
1…Is there currently a plug in or something that would allow the installation of this custom theme on multiple “separate” domain names
2…Is there a plug in or something that I can use to change the header, colour scheme and/or background picture on all these from one area?
3…Is there a plug in that I could use maybe to do these one at a time? (example) change the headers, then change the colour schemes etc

The readers’ digest version:
Let’s say I have 25 similar blogs. I want to use my custom template for each of these blogs, they are all the same format, but I need “each” one of these blogs to be a different colour, and have a different header and a different background main page picture.
Think team sports

From what I’m understanding I can go to each one of the blogs, and I’ve had the template set up to change the colour coding, change the background picture, and change the header in one area (so it’s easy to find)
so what i’m looking for is something that I can do this from one spot. I log into a main wordpress site either my own or somewhere else, and I can update and ftp sort of thing from one area. or have the files already residing on the site.

Hopefully you understand what I’m saying or trying to do.
If you know of something that could help me out, that would be great
If you don’t, then there’s a project for someone, as I’ve run across this scenario before.

thanks in advance
Happy Holidays