You are both right about the black and white trims. Black trims were the first on the market. However, most homeowners have switched to white trims for the interior. I would probably put the black ones outside because they show less dirt. Check the trims that you are purchasing to find out which light bulbs they will take before worrying about PAR and regular flood lamps. Some trims will not take both. don't mix the light bulbs in one room. Decide which lamps you want in which area and stay with it. If the recessed light you are using can use both types of bulbs, then you can decide if you want a warmer light or a brighter light in the area. At times we have mixed these by putting the brighter, whiter PAR lamps in task areas (i.e., kitchens) and the more yellow incandescent bulbs in the living areas (living room, dining room, etc.) depending on the colors that were being used. If you are contemporary, the PAR lamps are wonderful. If you are traditional we have used the regular reflector lamps. This is all a personal choice and I would suggest that you look at how both lamps would look in your home. Remember, you can always dim the PAR lights down and even though they will be white looking, they won't be as bright.

The mosaic installation is indeed lacking. The wall tile, there are usually pattern restrictions when installing tiles that are long like yours, if they are over 12" in length. The reason is that often times these tiles are bowed, they are not perfectly flat. Take two of the tiles, stack them so glaze is touching glaze. Do they rock against one another? Installing these tiles in an improper offset pattern can result in the "high midsection" of one tile being next to the "low end" of the neighboring tile. Lippage. Grout colors, if powdered grout was used, I'll dry mix all the powder first, then portion it out as I mix batch to batch. That way you don't suffer from color changes due to differing lot numbers. Most color changes come from water. Too much water used in this batch versus the other batch, too much water used when cleaning up this section versus the other section, etc. Some color variation can blend out over time once all the grout and thinset is equally cured. The grout can wick moisture from the thinset behind the tile. Even slight differences in moisture can cause grout to shade differently. Acid washing? That can kill the color as well. I never use acid on cementitious grout. It kills the color and the texture, who knows what dilution rate was used. Definitely bring in supervision. You have issues. The mosaic is bad. If the wall field tile is large format and the manufacturer has published restrictions on how is should be installed, perhaps those instructions were not followed. Basic TCNA installation instructions not being followed, caulk versus grout used in the changes of plane, for example. When I see sloppy finish work, it does make me curious about the attention to detail given to the waterproofing behind the tile, the stuff that can't be seen. Good luck getting this resolved to your satisfaction.

I think dark brown grout would make the tile colors pop.

personally I think trying to match the blue would be too matchy. (note I'm not a pro. I am a graphic designer who is extremely color sensitive, but I'm not an interior designer, so take that for what it is.) So, my vote is #9. It's a grey that compliments both the blue and white tile. And it's not too dark or light, so you can get that reduced contrast look you're thinking of. However, did you get that sample color off the web? It's far better to go see it IRL. Take home some samples and view them in the room where they're going, next to your tiles. See if the vendor will actually grout some sample tile for you if possible.