I'm not using compatibility mode on Win 7 either, but I did have to used the Graphic Rules Fix to get the game to recognise my much newer graphics card. And to get rid of the black boxes and increase my graphics memory, etc.
The UC is much easier for when you do a full reinstall, I find, but I have more than one or two disks. I have just about everything and reinstalling from scratch using disks would take hours probably :cold_sweat:
If you choose to keep Origin installed you can even get Origin to repair the game in a situation where a full reinstall may not be needed. I understand though about the whole downloadable content only thing. The UC was a free gift for people who own Sims 2 on disk probably to encourage them to use Origin, but as mentioned above, it is possible to run the game from the .exe and not Origin anyway. No need to be online or anything once the game is installed.