I would go with a 6 x 24 type tile -something long and narrow to elongate the room. You can install them randomly - similar to how the hardwood is installed. (doesn't have to be a straight subway/brick look). Also something that has a non-slip rating. A mosaic would look nice, too if it wasn't too busy.

The bathroom looks small. We are redoing our bathroom and it looks to be about the same size as yours. Our tile guy suggested something that size. I was thinking 12/24 but then he pointed out how it would look choppy because of the size of the bathroom, and recommended a narrower tile. We are using Happy Floors Neo-Tile. It has a high non-skid rating. It may be too modern for your bathroom but you may want to check it out. It comes in a tan color that might look nice in this bath. http://www.happy-floors.com/brands/neostile/

I would go with a warm dark walnut porcelain wood look tile planks. Try to compliment the darker shower accent tiles.

Good idea, it would pop against the white headboard, too.