I like the concrete bloc walls. They are becoming quite fashionable today. I'd keep them in the natural concrete color or if they have been painted, a color paint that resembles concrete. The concrete walls give a hard and cold impression so I'd choose wood flooring for the floors. The combination of a warm wood on the floor and hard, cold concrete on the walls is a nice one. Brighten the space with colorful modern art.

Take a clue from the pics....Do it's hard when you're starting and everything needs doing. Find a picture you like and use that as a guide. Do you like the looks of the colors in the two pictures above? Very simple and straight forward with beige/gray bricks and white and black accent colors for shutters and trim.

Love blue tiles. Depending on how much sun and how hot your pool gets in the summer should dictate what color it is. We live in Arizona, so cool blues work best. Our neighbor has brown tile and a dark pebble tech pool. Looks like a swimming hole and gets really hot - 94% water in the summer. They obviously didn't think it through.

I think, like you said, due to the fact that there's a larger space when it comes to the hotel lobbies is the reason as to why it works. I think that no matter what you put on the walls (whether it be concrete or marble) will result in tiles not working out. The industrial look tends to be exposed brickwork anyway, or cream or white colours so maybe that's an option you could look into. What did you end up doing?