You will get aprox 50 Square per gallon of Hydro ban if you apply it over Green EBoard or cement Board on the rough side. You will get closer to 60 Square feet of coverage over the smooth side of Green EBoard. Can you measure out the exact square footage and what you plan for a shower base and the walls. The Kerdi Drain is an excellent product but a bit on the pricey side at $130.00 Nobel makes a sweet little adapater piece for a regular drain $12.00 that can give you a liquid tie in point. Contact Laticrete for approval - I spoke just two days back to Eric at Nobel head office and he told me about this greta Nobel product. I have some of those en route as well. Eric is a great guy - email him and he can tell you all about it. I wish he chimed in here from time to time... Eric? Where are you? sales@noblecompany.com JW Here is a link that might be useful: Nobel products for your bathroom renovation

Caulk. Pedestal sinks move. The caulk will "give" with the movement, whereas the grout could separate, crack, or fragment with sink movement. flexibly, Mongo

It used to be that 1/16th was called out for rectified tiles. With the new specs for manufacturing, you start getting more variations in tile size. Even in rectified, believe it or not. The new installation recommendation, which has actually been around for a few years, is to have the grout line 3-times the size of the variation within the tiles. This usually comes down to an 1/8th inch grout line. Lippage can also be an issue based on the pattern. A stacked pattern might not show lippage whereas a running bond could. The larger the tile, the more chance you have of lippage with offset patterns. That's all due to the tiles not being perfectly flat. A slight warp, pillow, or pringing (like the pringles potato chip). The grout needs depth. Otherwise it'll just pop out. So a 1/32nd gap with a beveled edge, you may not have durability, because the installer may not pack the joint (if there even is an actual joint) with grout. So: Not to dump on the guy who plans on going 1/32nd...but I'd nix that. Someone who tells me they're going with 1/32nd, I think they're just going to lightly butt the tiles together and get whatever grout penetration they can. And it'll likely be nothing more than topical grout with very little actually packing whatever gap there would be between the tiles. With the new specs, 1/8th inch is the new standard. You could still go 1/16th if the tiles and pattern allow for it, the installer is comfortable with it, and it's called out in the specs...but I'd not advocate going less.

I am worried that you will not like the bright white grout, since you were already concerned about the tile looking a little too gray with everything else? (Obviously, you are worried, too!) I think a slightly beige-y grout would be just the thing you need to pull it all together perfectly. It will pick up those beige tones in the marble. Maybe people could give you some pics and tell you their grout colors--it isn't something usually named, but it is kind of important, especially with subways.