LOD is a pain, but is by no means strictly required. So that can also be handled down the road should some new method be found to work with it, or should it actually get fixed properly.
As for the rest, really, with the 4 mods I have out now, everything is working as expected other than navmesh issues. I've touched on a large enough cross-section of features to know the CK can be used to do great things.
Lod is not strictly required?
Surely not if you can live with the distant view of few meters , are not annoyed by custom pop up of huge buildings and stuff in front of you and you can eventually stand very very bad Looking landscapes from distance just because of nonexhistant or bad looking lods ..
Well I have 9 mods out there and I coudl manage to make them work , but yet I define them as "minor mods" even if they regard new content , totally made from scratch armors ( not retextured or remheshacked Stuff ) wich required a LOT of work , Really a LOT of .... "Work" not much in the 3d tools , the PS stuff but in the NIFScope Alchemy brainstorming , trying 100 different hacks and stuff to "make" it work in game ...
and we are not talking of weird stuff that is not appearing in game , but just normal armors stuff ...
Modding Skyrim requires a Lot of External work of CK that the CK is just right now a handfull tool as many others that allows you to create levels , but still lacks a lot of "working" features that coudl allow to realize the properly called "mods" ....
May be I may sound harsh or look "unpolite" in my answering , but is not my intention .... For me ture mods are the ones that add new Content that is "fitting" with the game , I do not even consider stuff like Pink Dragons or boobed dolls ... What will make the Game be more interesting and appealing for people in future are "content mods " the ones that will add quests , things to do and new landscapes to see ...
The new little stuff may be cool for some minutes to play with .... having the 100th different hammer with the shiny surface or the 1000th different skimpy armor how long will keep the players play with Skyrim ?
I think this is what the developers should relally consider when "helping" the community to make the mods ....
the real modding starts where the true new content is added , not the random stuff added in the forms of Just "items" .... I include myself among those modders as well ...
Not think of my mod for example for conan outfit ... so far I did from scratch the conan outfit , took over a month of work of wich 60 % trying to make it work ingame and 40 or may be even less in external tools ...
Then I just placed the stuff on a table in a cabin ... no quest no things to do , etc .. This is what usually is done for the 99% of the new content ... you either pick up somewhere or you craft ...
well after having tried the new toy ... and having done nothing to get it .... what will keep the player still playing the game?