Is there a way to check a mod (example, I like a lot of the hairs and things on tumblr that you can download. However I believe one of them broke my game at one point and I really, really don't want to install it in a game and have to uninstall it after.) Unfortunately, sometimes the sims 3 cc makers don't always list what they're incompatible with. I can't stand testing them.

I recommend that you convert all your Sims3Pack content (except Store content) into Package files. You can do this with Delphy's tool. It's very easy to use. That way is very easy to uninstall what doesn't work. What I do to check whether my latest package files are good or not is to REMOVE everything else in my Mods/Packages folder BUT the NEW content. That way I can easily check in game whether that content works. You can also use Dashboard to check you package content.

Just a couple of suggestions to add to Naus Allien's advice:

If you do not want to convert 3 packs to .package files you can use: Delphy's Custard to check contents of the 3 pack. Crinrict has some tips On This Page. Note: Custard is not meant to be used to check world files. The world files will show as being corrupt as will lot files.

Delphy's Dashboard is an excellent tool to check package files but please keep in mind it is not 100% foolproof. It is recommended to use the tool to scan the Mods/Package folder. Scanning your entire game folder will produce results that appear to have multiple file conflicts. For more help with using the Dashboard see Nona Mena's Understanding Mod and CC Conflicts with Delphy's Dashboard.