The super fast awd stuff youve seen with no front movement probably has alot more going susp wise than youd think, its not easy to go fast with awd at a certain point.
I watched a few more of the videos, that last one can see it wheelie cause the front is so tight and then that makes it spin. Needs opposite of whats going on now, front slightly looser and rear alot stiffer but both with more shock control. Dont they make shocks with light coilover helper springs to mount in stock shock location? A front lsd will help some also once you get the susp movement undercontrol.
good luck, ive always liked the garnet tys