No you can turn the turbo off,
I'm not 100% on this but I think you'll find more import don't have the import papers than do.
Personally I wouldn't be buying an import from someone who claims or actually knows nothing/very little about the car they own, unless YOU know exactly what your looking at.
I haven't owned any turbo that's still running an airbox but I imagine you would hear the turbo spoiling obviously not as loud as a POD though