Tell your wife the backsplash cannot be all the same everywhere, as it's a focal point that takes your attention right under that massive hood. This will make her give some thought to the small variation in hue you will add in to the backsplash and that will somehow culminate under your big hood where you already have a focal point. You have a low-contrast color scheme. White and pale are close in color value. So, you could just vary slight differences in hues and concentrate them there. Doesn't have to be anything "representational" at all. In art, representational means it shows you something that represents a real thing you already know how to see. Concentrate accents in one area, any way at all.

Argh. Photobucket is giving me fits this morning. Here is photograph of the fireplace in living room.

"preference is porcelain - durable and easy on the budget)." Nothing you have mentioned is easy on the budget. 1) If your subfloor is wood have you checked deflection to see if tile is a option? Rip up, adding underlayment, baseboard R&R, cutting doors etc. will be required at a very substantial cost. 2) 18x18 tile requires minimal subfloor variation. Expect to pay $$$ to bring it within tolerances. Be sure to purchase rectified tiles for 18x18 yes again more $$ 3) You will need to find a installer capable of installing 18x18 tiles. I recommend a installer that uses a lippage tuning system. Again more $$. I suggest first have a professional tile shop (not a box store) give you a estimate for a large format tile installation. It is best to know the real world price of your project before making yourself nuts about the color. IMO

Well! I am glad. Because IF you were my client, I'd have made you rip all the bedroom carpets to hardwood, before you tackled a lick of trim. : ) Realize too, that an attempt to turn a perfectly lovely 1990's contemporary shell INTO a Craftsman......? Can fail you and empty your pockets. You can have " the beef" ......with care , a great result too. A five inch window casing, NO change in size/trim at the top, for just one instance. Simple single panel doors. .....glowing hardwood. Also a lighting plan that is cohesive. ( kitchen ) If your new "help" is very honest,? She is going to rein you in a bit, slow you down a bit. Resist the urge to fire her, as she will be giving you good advice should that happen. Along with, finish that which you start, and don't peck all over the house. Rome isn't built in a day. A designer can help you focus your efforts for most appropriate result and value.......over time. Good luck!