At this point I just relied on the self-stick of the tile. They are so light and the sticky covers the entire back so I don't foresee an issue. I did make sure to thoroughly clean the wall with a TSP cleaner prior to installation.
As far as edges, there is really only one and so far I'm leaving it as-is while I decide if it needs something. The right side wall had molding and I able to sneak the edge underneath it, also was able to go down 1" behind the countertops. It's just the left side where it hits the "living room" that I may do something down the road, probably a thin wood that matches the cabinets.
Ed & Joie
2004 Vectra 40KD
Freightliner Chassis and Cummins ISC