The mouse behavior is coming from the fact that the default UE4 mouse navigation is world aligned and of course doesn’t take the SpaceMouse thing into account. However if you do Maya style navigation (Alt + (LMB) Drag) then everything will nicely reset. It is of course possible to design some logic for the viewports to counteract this phenomena buut I have more important things to do ATM 
I didn’t experience those jumping forward/backward yet, can you put up a video about it, with debug info turned on in the SpaceMouse editor settings? (with OBS and unlisted youtube video or similar)