I wonder if this is where strikecnc got the idea of not using proper bearings on the ballscrews.

Anyway, I think the easiest way to solve this is to buy a pair of FK/FF bearing blocks since so long as the extrusion is long enough you can drill a hole in either side and put the new bearing mounts in. That's assuming the ballscrew end machining is standard, what does it look like?

Also, I'd solder those motor connections as if they work loose whilst the machine is running the stepper driver could be damaged.