It doesn't crash if you install the STRINGS files from the /strings folder in the BSA into the Data/strings directory. I have not merged the other folders from the BSA with my installation, so I'm still getting a few errors on load.
Just by unpacking the Strings from the BSA will not let you see any of the new architecture. You need to open SkyrimEditor.ini and add the Dawngaurd.bsa manually.
Scroll down until you find the [Archive] section and then add Dawnguard.bsa to the line that reads
SResourceArchiveList2=Skyrim - Shaders.bsa, Update.bsa
Add Dawnguard.bsa so that it reads -
SResourceArchiveList2=Skyrim - Shaders.bsa, Update.bsa,
Dawnguard.bsaIf you do this first, there is no need to unpack the Strings from the bsa file.
[Edit]
You will still get a lot of errors because the CK is not fully ready for some of the new content, but it will let you use the new objects in your mod.