Splitting out chat about your specific queries:
Re: Concrete: I haven't ever lived with polished concrete - I would think it would be sealed so that stains wouldn't be an issue, but YMMV. I have lived with *unfinished* concrete (before I put real flooring in), and it was *hard* and *cold*. Radiant heating in the floor would at least take care of the cold part...
Tile will have the same issues as above, plus grout lines. Have you looked at something like bamboo? Hard, but at least a bit warmer, and pretty hard to damage. Linoleum - the real stuff - will be as hard as whatever the substrate is, but is also environmentally friendly and comes in nice sheets so you have no/few grout lines. If you don't care about environmentally friendly, vinyl will do the same thing. If you're willing to spend enough money, you can get your entire house floor extruded as a single sheet. :)
I like the idea of hose-down wet rooms, and someday when I redo my bathroom it absolutely will be that way.
For grout issues, I think the least painful way to deal with it is: very thin grout lines, that are not white. You could also look at single sheet vinyl, again. There's always the trade-off, though, that a single flat surface shows soap scum to perfection in a way that smaller tiles don't.
Instead of building in something like sweep-in baseboards, I'd just buy a Roomba or 3. Along those lines, one thing I really loved about my Fisher and Paykel dishdrawers was that I could always have one dishwasher load going and another being emptied/filled, so I never had piles of dishes lying around. More automation == less work for me.
There used to be a kitchen forum on Gardenweb that was full of cool ideas to build in but I haven't checked it in years.