I recently made a few lap sized quilts with minky backing..
I washed/dryed all cotton fabrics to preshrink as the minky is poly and won't shrink.
Used 80/20 batting too.
When cutting, i used a lint roller to quickly clean up the fluffies.
I spray basted one and pin basted the other - never had any bunching either way.
Used 90/14 Topstitch needle.
Walking Foot to quilt - I think this really helped.
I used Poly thread - Superior Bottom Line - in the bobbin so it would 'sink' into the minky and my Aurifil 50 wt on top.
My notes-to-self afterwards: Don't ever get so ambitious as to quilt anything larger than lap size minky on the DSM as it's a lot to wrestle with under the needle.
I'm sure others more experienced will have more to add
Look forward to hearing other ideas and seeing pics of your minky quilt!