Some issues I have encountered are strange wiggly-jigglies at some points and a horizontal twisting on direction change, possibly a bounce as well...

I am sure most of these issues are weight related. I am asking a lot of the stepper and G2 belt to stop the motion of 3 kg and restart it in the opposite direction, roughly the equivalent of accelerating 6 kg. I am not considering this a fail, however it needs help.

Maybe a screw drive or another belt on the far side of the bed. Suggestions?

The blue tape is acting as a temporary bed flattener. Eventually i will get around to having someone mill it down...