Bmax4 II help

[OneKiwi]

Hi all
It may well look like Ill be getting a 4 II and want to know a few things.

Is there another shell that fits? B4 III?? Or really close?

What pistons are recommended, high grip astro. I currently have the stock black and white tapered, anyone try the 2 hole 1,6/1,7

Do the AE pistons fit?

I can't seem to screw the rear part of the slipper down snug. It binds the bearings. I have to back off a couple of turns.
Is anyone running a spacer or something here

How do I adjust toe in the rear?

Thanks