Is there a way to export settings for C# formatting at a project level so that we can put the settings file on a repository and everyone can use it without affecting other projects that are using different formatting styles?
- For Visual Studio C# environment settings, you can Export them from Tools->Import and Export Settings->Export Selected Environment Settings, then save the file. - You can store this file somewhere on the network, in Source Safe or TFS. - Then the other devs who want to use those settings will Import them Tools->Import and Export Settings->Import Select Environment Settings, select the file and press import. 
- It can also be loaded from command line, or a desktop shortcut - Devenv.exe "C:\MySolution.sln" /ResetSettings "C:\MySettings.vssettings"
- Consider the Code Analysis Policy Editor in Check-In Policies. 
- If what you are looking for is not built in, you might need to look for an Add-in, CodePlex has over 500 of them. If you don't find it, you might have to make Make one. 
- Another possible solution is to bring the teams together in a coding standard meeting where they can agree on a common coding standard, then use a tool like CodeIt.Right to do the code refactoring automatically.