: I am wondering if the 3M green pads will rough the varnish well enough
: between coats? Any thoughts?

I use the green pads between each coat of varnish, even in its green stage, it seams to help knock down any dust spots and even helps with small sags.

:What is the concensus on the number of varnish coats one should put on the kayak?

Depends on the look you want. I think four coats is the minimum when brushed on I like five coats of varnish. With each passing coat I think you get a richer and more consistent look no matter if I am using a Satin or a gloss varnish.

JAG