Hi Patrick, 

i agree with your instinct and i have always done the rubstrips and then refinshed afterwards.  its a little bit challenging to get a clean line with dynel so i also keep a bit of flat-black rustoleum and actually paint a perfect line around/ontop of my rubstrips as a last step after i have done paint/varnish.... so 1) install strips, 2) hull paint/varnish up to the edges of the rubstrip 3) flat black rustoleum on top of rubstrip/perfect line ontop of paint if i feel i need this step.  picture below (after step 3) shows the nice clean look it gives.

on your second question, if you are doing a fleet i would not buy the rubstrip kits.  i bought one yard of dynel (55 inches wide) from jamestown distributors and small container of graphite and have used it on 5 boats already and have plenty left.   a bit more expensive than one kit....but cheap for a fleet.

hope that was helpful.

h

   Thanks H! I really appreciate your response. It's very helpful and the black paint isn't something I'd thought of but really like the idea of a crisp line. Many thanks from Colorado!