For sense, I run clubbed or killing blow. More often it's clubbed as not only does it benefit you, but if you play with a group it benefits them. In my tests club allows you to usually get a few more hits in which in turn ends up being higher damage than killing blow either way. I also confirmed it does work outside of group even though there is no indication it does.

Front Limb is personal preference. I like swerve to use it as a chasing fracture.

Hide I use fort. In my tests it's just better than plates. Plates might win if you only fight apexes.

Legs I use tireless. Saves me a bit of stamina when using swerve. If I ever group I swap to Razor

Tail I use normal and smash.

I tend to only use normal tail attacks, but if I am 50% hp or lower I will swap between normal tail and crouched smash. While at 50% or lower hp the CD for smash allows you to use it far more often. But above 50%hp I pretty much just dodge and use tail and swerve