That is the way you would traditionally end the tile, but all of the way up to the ceiling would be a statement. I don't think you can go wrong.

I think it is fine and you should be happy with it. It's a small area and most end (most) end their tile at the end of the cabinet yet given the short distance it was probably best to go to near to the wall edge. If it's not grouted yet go with white/light grout... that's my opinion so it doesn't stand out... not that it looks bad as it doesn't... yet do you want it to blend or you want the grout darker to bring attention the the smaller space?

I would remove the side splash. Would look so much better. It`s back splash - not side splash. I had the same dilemma when doing my back splash. I said i wanted side splash, tiler said it would look better with no side splash. He was right.

Eliminating side splash would eliminate dilemma (s).

Going all the way to the ceiling will get in the way of being able to open your cabinets properly. I have to agree with Angel 18432, I would consider eliminating it or even stopping it at the edge of the upper cabinet.

There was no reason to tile the sidewalls. You should have stopped at the corners

I think the side tile ok but I also think iit looks "boxed in " and therefore makes it look smaller I would just do the back