Very nice. You should get many years of enjoyment out of it. It is a chore keeping 5 taps full. One of mine is root beer. If you haven't planned for it already, definitely look into the gas assist struts. That top will be extremely heavy.
Nice job. Looks like you will have a pretty sweet set up. Personally, I would stain it a medium color to accent the tile. Maybe a pecan or even as dark as a cherry would look nice. Polyurethane would work great and be fairly easy to use. Problem is you will need light in that space to make it...
Yes, it is a fast fermenting yeast. Did you make a starter? I do a 2 vile 2 quart starter on a stir plate and with the wheat yeast I need a blow off tube for about 2 days. Usually finishes in about a week.
Yes, this is normal for this yeast. I use it frequently and the banana notes are desirable. Wheat beers are my favorite and I use WLP 300 for my dunkelweizen and WLP 320 for my regular wheat beers.
I do not think so, but I will check when I go back to work (Lowe's).
Heckels is correct, you need to account for additional space for a gallon jug and a blowoff tube. I have space for one per carboy and often need it.