I started working with the CK at release, but all the bugs and a framerate drop problem I had forced me to drop my projects for a while. Now that things are fixed on my end, I'm hoping that in the downtime some CK bugs have been patched.

Here are some bugs I remembered seeing during release:

1. Building, landscape and various outdoor objects sometimes vanished from the game world.
2. The navmesh bug.
3. Discolored npc head when creating a new character.
4. CK crashing here and there.

Have any of these been fixed? Are there any old bugs I missed? Are there any new (hopefully not) bugs that have appeared with new patches?

1. Almost fixed, IIRC. It still happens on the odd occasion but it's much less frequent than before, to the point where it's no longer a real issue (from what I've experienced anyway).
2. That's fixed, finally, as it was an issue with the game and the CK.
3. You need to export your facegen textures and include them with your mod. It's an easy thing to do: http://www.creationkit.com/Dark_Face_Bug
4. Still crashes. Just save often.