Let's rule out some generic problems first.
Framerate: The sims 3 haves this little issue where the game tries to run at ridiculously high framerate and thus chokes your poor videocard, making the game slower and causing crashes. The easy way to prevent this is to go to your videocard's control panel and force vsync and triple buffering for the sims 3 and each of it's expansions.
Cache Files: The sims 3 creates cache files to speed things up, however, it doesn't clean them up of old unused data. Deleting your cache files will make the game slower the first time it haves to create them again (first time you enter a cas page, or start a world, or open the build/buy menus), but if they were cluttered with things, you should see a speed up afterward. Additionally, the game also caches script files, which are the ones that rule on how things behave. If the game forgot to change/remove those when patching or you at some point had some custom content that used scripts and is no longer compatible, deleting the script cache will help a lot.
On the same place you found the DCBackup folder, delete or move to a safe place: CASPartCache.package, ScriptCache.package, CompositorCache.package and simCompositorCache.package. Additionally, you might want to delete the files inside the WorldCaches folder.
The sims 3 does not do a good job at cleaning up some things, for example, taxis sometimes get stuck and never leave the streets, standing in place or roaming around forever (these accumulate over time, eating memory, note: this is unrelated with bridgeport, there are a number of ever-roaming taxis on the streets as scenery to make the city look busy); Sometimes sims forget to turn off radios or tvs around the town and this eventually starts causing audio delays or sound effects outright not playing. These two, however, shouldn't cause problems on a brand new neighborhood.
Mods, unsuccessful patches, and even outdated video drivers can cause odd problems as well, did you updated WA/Ambitions after installing late night?, are you using many mods?.