Bah!!
Instead of clogging my registry with 100 msi programs, how about focusing on getting right next time? I'd like to some sort of integrated program(I'll call it the "OFP update Manager") come with the next version of OFP that makes the whole mission/addon thing completely painless and error free for the folks who just want to PLAY the game.
Perhaps mission makers could post XML files on their websites that contain all of the info for their missions. Maybe even a browser plug in that integrates with "OFP update Manager" thingy, that would handle special links mission makers put on their site.
The user could wither click on a link, a have the browser plugin load the "OFP update Manager", or the user could put in the URL for the website where the XML file is. The "OFP update Manager" would then connect, get the XML file, and display a list of missions available. Then the user would click on the mission they want, and OFP would magically download all of the necessary files, and install them automatically.
An "update" feature could automatically go out to the net, and download whatever updates are necessary for the various downloaded missions and addons.
Something like this could even be used to install official patches for OFP.
Along with a BIS supported standard to keep addons from stepping on each other, this could make things 1000% better.
Just my 2 pennies.