#1 is pretty good, assuming your colors in the pic are halfway accurate - are they? Cabinet and trim ooks more greigey beigey-brown than straight gray.... which IMHO works well with the wood floor.
#2 white - no, unless you can persuade your brother to change the cabs from greige to same white
#3 - another no. To chopped up, black doesnt relate to anything.
Can you get more matching white tile for under the tub? Keep it simple - repeat elements, no more than 3 colors max. A good rule of thumb is 60% your main color, 30% secondary, and 10% accent.
Q