So here are the steps i take:
Extract "meshes/actors/character/animations/idledrunk.hkx" from bsa
convert from hkx to kf
hkxcmd exportkf skeleton.hkx idledrunk.hkx idledrunk.kf
open "skeleton.kf" and attach "idledrunk.kf" to check it working. it works. close.
open "idledrunk.kf", go to NiHeader, change the first under "Strings" to "idletest01" (from "idledrunk"), save as "idletest01.kf"
convert back to hkx
hkxcmd convertkf skeleton.hkx idletest01.kf idletest01.hkx
place "idletest01.hkx" into "Data\meshes\actors\character\animations"
start up Creation Kit, go to "Gameplay" -> "Animations" -> "Insert Sibling", and choose my "idletest01.hkx" file
now when i press "insert child", i get a window to select form. HOWEVER when i press cancel, open up the animations window again and press insert child (there is now a "LOOSE" entry), it gives me a blank entry, which i name "idletest01" and then close.
i go to my "AI Package" -> "Idles" -> "New", and try to find my new Idle - but it isn't there. However, neither is "IdleDrunk", only "IdleDrunkStart" (and Stop). I noticed those entries on the Animations Window under Character\Behaviors\0_Master.hkx -> LOOSE -> IdleDrunkStart
So i think my problem is making a new idle recognizable as an idle, by the ck. But i don't know, does anyone have any suggestions?