[4] Any tips on when cutting end pieces to fit keep the splintering to a
minimum? I have been using a pretty good blade (100T 12inch) and going slow
and this has been working good, but occasionally I do get a bit of a rough
edge.

If you can, remove what would be called a 'throat plate' if you were using a
table saw. I'm not sure if it is called the same thing on a (S)CMS. Then
replace it with a block of wood or MDF that just fits in the void. An there
you go... a zero-clearance insert that will minimize splintering.

-John