Tattooed and Dusty wrote:
...

So the question. I think a big chunk of the success of this joint is
due to my new fancy Lie Nelson Rabbet Block Plane. It rocks,

Lapping the sole might help to fix that...

and is on
sale at woodcraft this month. So finally the question, when I tighten
down on the brass screw to lock the blade in place it frequently
skews
off the the side. ...

You might try putting brass shim between the screw and the blade.

--

FF