Looks more like a Brew Bunker than a beer cave to me...
Especially with the concrete block walls...
Good idea to hold off on installing the floor tile until the windows are in. I'd even wait until the ceiling is installed, so that you don't need to worry about the tiles being buggered up.
Thinking about what I would have done, just a little different, compared with your design/layout... Install a dry-well (with a pump going outside, or to the sink drain, assuming you'll have a sink in the room) in the floor, then slope the tiles so that it drains to that point. Install a hose spout on one wall, so that you can simply hose down everything when you have a boil-over, or spill. You could use the same hose fitting for your wort chiller feed...
I think the vented hood is a great idea. With using natural gas, it's less about removing gas fumes as getting the water vapor from the boil out of the room.
Do you plan on fermenting in that same room? Making a fermentation chamber, or just going with ambient air temp?
Wondering if there was any way you could have painted the walls in a speck patter with most of the colors that your wort could be. That way, it will hide any spots... Although, you probably don't want to do that, so you can see them in order to clean them up. No point in leaving the wort on the walls, attracting all kinds of crawlies...