I use Crowbar, and a python script to modify the speed values efficiently. Are you using that decompiler? The only issue I've had with it is needing to disable IK on the antlions / antlion guard.

How did you manage to compile some of your NPC speed mods without errors? When I try decompiling them and recompiling, there keeps being errors such as duplicates and unknown subtract values. And when I fix those errors and then continue to recompile, human NPCs would have this weird rotational error where they’re occasionally way off to the side while firing.

Vehicles -> I have done another pass on the steering.

Corpses -> I'm just deleting the ragdoll managers now. Maybe that fixes it?
Hunter -> Added and increased values.

Permanent Corpse mod doesn't seem to work correctly in episode 1

Thought I changed the hunter values. I should recheck. The scout car SEEMED fine... I should recheck.