I hear you. We just had a fence put in, and I want to stain it. A medium dark brown, without too much red, but not gray looking... I've got 5 quarts and three sample size stains, and so far nothing is exactly right.

I would NOT add faux stone to your home. Painting the blue out with a darker gray or even a sage color would enhance your home. Do consider either painting your garage doors the same color as the new siding color you choose. Or go in the opposite direction and add the cedar look garage doors to coordinate with the cedar on your future (very lovely) home.

The yellow is pretty. Another option that works well with the gray and black is a raspberry color like SW Cerise. A dusty plum can be pretty as well. This is SW Plum Dandy.

Generally, hardware is viewed by room. In a kitchen, it is possible to mix finishes for a more custom look. Really just depends on your taste. If you are matching hardware by floor, you really have nothing to worry about, unless it is all the same size shape and too repetitive and not conducive to the item it is placed on. Down a hallway, it is nice to have unified hardware as they are often all in one's line of sight. Rooms behind closed doors, go for what you like inside, does not have to match what is on the entire floor. My advice for your kitchen if it is not too late, it to find hardware that come in that satin brass finish you like but are handles and not just knobs. I assume you cannot return the ones I see in the picture. My suggestion then would be keep knobs on the bottom drawers, of which you have many and get vertical handles for the uppers in satin brass, just to break add interest and break up the repetition a bit. Ideally, I would do the reverse horizontal or cup handles on lowers and knobs on uppers. But go with what you love.