1. The bottom row should have a gap between them and the granite (a strip of cardboard or wood the right height can help keep it nice and level), and I guess you'd grout it instead of caulk but check with the pros on that. It SHOULDn't be shifting since it's all hard stuff in the same plane, but matching caulk would be safer.

2. When I did this, I cut the bullnosed 3x6 in half and used that. I also had to cut down a 6x6 tile with 2 bullnosed edges to become a corner subway that was edged on two sides. Limited tile selection I guess! But my tile was a handmade sort of irregular stuff and I was able to get away with it.

Another way to end the tile is to do an edge with skinny trim pieces. That looks very nice.

The cardboard idea is a good one. I just rested the bottom tile on two spacers to get an even gap along the tile. There should be a slight gap that gets filled with caulk, not grout. As I understand, grout shouldn't be used between the tiled plane and another surface. A flexible caulk won't crack if the cabinets or floors shift.

As for ending the tile, I used the bargain bin white subway tile from Home Depot, but didn't think to purchase any bullnose pieces. I just ended them in a straight line, just past the tip of the counter, with the finished edge out. The cut edge (on every other tile) I turned in. I was very careful and make everything look pretty clean.I then used a small line of caulk on the outside joint.

thankyou folks....just the tips i needed. appreciate it!!

We did the lowes subway and also had a 4" corian backsplash. We used 1/8" spacers between the bottom of the tile and the top of the backsplash to ensure a consistent line. We also definitely caulked instead of grout because you never now if there's any flex between the counter and the wall. Essentially, if there was a surface where tile touched something OTHER than tile we caulked it with matching caulk.

We used the 2x6" bullnose pieces on ours plus a couple of creative corner cuts on the 6x6 and 2x2 corners. Below are the pics. It wasn't exactly what I wanted (which was to just end on a bullnose that was 3x6) but those aren't available in regular on the shelf stuff.

Here's how we did it

If you choose the right tile manufacturer, bullnose edging will be available on any side(s) you might need.
It's hard to see in these pictures but, the tiles along the top row are bullnosed along the 6" edge and the ones on the righthand end are bullnosed on the 3"side.
There are also corner bullnose pieces available