So, I just was trying to make a Sim. But they didn't show up on the screen, so I spun where the Sim was supposed to be on the screen. It flung me off of the CAS map, and the Sim was standing in the trees. It was really weird...

I don't know if this has to do with InTeen in which I just installed (I couldn't find one for the DD, so I just installed the NL InTeen, since NL is in DD). It gave me all these warnings to install THIS ONE ONLY.

Could this corruption be because of that?

Hack troubleshooting 101: Back up your game, remove the hack, and test to see if the problem remains without it. That's the only way you're going to get that question answered.

A hack conflict is not remotely the same thing as "corruption", by the way. (That word is being thrown around far too much lately!) The vast majority of problems caused by hacks are solved by simply removing the hack.

If you have Double Deluxe, then Nightlife is definitely not the correct version.

This might be handy:
http://www.simbology.com/smf/index.php?topic=1228.0

You'll note that Celebration Stuff uses the Open for Business game engine, so that's probably what you want, unless you have the Store Edition installed.

If you do have the Store Edition installed, then the hardest part is determining which version of the Store Edition you have. The updated SE is compatible with Apartment Life, but you may not have the updated version. You may be able to figure out your game engine by looking at all of the release dates and trying to match the release of Double Deluxe with a specific EP:
http://en.wikipedia.org/wiki/The_Si....2C_and_add-ons

Looks like Double Deluxe came out between FreeTime and Apartment Life, which would suggest that the non-updated Store Edition which shipped with DD uses the FreeTime game engine.