I'd want the trim marked with red changed to the darker color. The horizontal pieces look OK to me, but they could go dark as well.

If you are up for changing things, and it's possible, maybe remove the curved roof on the left.

Is it paintable or does it come in a color to match siding?

You will need to ask the builder.

Also looking for suggestions on how to make rest of trim more pronounced and traditional (i.e. Dentil, crown)? Window boxes yes/no, color? Shutters yes/no, color?

The elevation is already rather busy. Not sure I'd be adding to or emphasizing what's already there.

I take it this is your house and you want advice about how to modify it.

The white flashing between the siding and the pent roofs should have been dark. Painting it would depend on the material.

The exterior cladding of a Shingle Style house should appear to be as continuous as possible from walls to roofs like a cloak, The designer seems to have not understand that idea or was unsure of the desired style.

A Shingle style house should not have corner boards or clapboards; the shingles should wrap the corners. The downspouts should match the siding color. There's too much white trim.

Are any of the materials synthetic or factory finished?

The siding color is a bit cold and dull and creates too much of a contrast with the bright white trim. I would paint the trim cream or pale gray but the gutters would still be white.

The biggest problem will be factory finished white metal — old wood or copper gutters and copper flashing are difficult to emulate with modern factory finished aluminum.

Additionally I'd make all the white siding the same gray/blue color as the rest of the house. That white siding detracts from the overall look and feel of the house.

This is flashing that the roofer installed. The same thing happened to me when I had my Gambrel roof re-done. They used a white flashing that cut the roof in half. I spoke to the owner and he agreed with me that it should be a color to blend. I believe my flashing was metal. It should be able to be painted.

The Queen Anne and Shingle Styles were popular at the same time in the US and have many similarities. This house is a bit of both so it is difficult to suggest how to improve it. If it didn't have the long 2 story rake at the left, I would say its more Queen Anne. Its a brain teaser.