I've done a few trial runs, it seems i can export animation on nif's in 3ds into nifskope, but the mesh itself doesn't seem to show up in game.

Just wondering if anyone has any insight to getting custom animations into the game, specifically on clutter objects. Or any animation at all.

Okay what you need to do is make your mesh and rigg the animated parts to their respective bones, do all the animation keys etc. and when your done include a bone "Scene Root" and in the dope sheet give it a text key tack with the appropriate text keys "start -name SpecialIdle -loop -at y" (or clamp, whatever you need) and "end". You can have multiple starts and ends under different animation names e.g. "Forward" and when exported it will put them as seperate controlled blocks in the kf file. When your done link the chain of bones to your Scene Root and export the mesh only (making sure not to flatten the hyeiarchy, then export as a single kf without mesh. load up your mesh in Nifskope and import the animation for it, then grab a vanilla animated nif and copy the BSX over so that you get the right flags set.

If you don't have an animation called "SpecialIdle" then you will have to either call the animations via script by name "Forward" unless you have ones like "Open" "Close" and make it a door object etc.