I like the idea if the marante garage door being the only warm feature in complete contrast to the materials and cool colour palette. The warmth of the timber and characteristics are a welcome contrast to steal the focus from the contemporary facade. And wi the timber shutters you mentioned, they are enough for it to make sense already. I like the idea of your suggestion regarding pop of colour, only I would interpret this pop by using a pure and clean WHITE! Some contemporary stainless hardware would really smarten and freshen the entry all year round. On the other hand, I like the idea of a timber door with horizontal timbers, perhaps stenciled randomly with numbers and letters, reminiscent of marine registration,or coastal buoy stamps. I would do these in coastal blues as in teal to duck egg blues, maybe even some mustard, only to have it sanded away leaving trace elements of the text, as if reclaimed docking timbers. Then, and only then would I seal it with a clear, satin varnish. Why not do something different? Doors are easily changed, and they leave a lasting impression, so every person lucky enough to stand outside it will admire the uniqueness and creativity of the homeowner. Maybe be a little clever, and include your street number on it!

A lot would depend on the door finish, as beadboard definitely catches dust collected in areas with high moisture/condensation, including steam and oils. They are both great looking, favorites. The benefit of the shaker is that it appeals to both country styles and contemporary classic styles including hamptons style. It can be dressed up or left rustic looking with a lot of charm and character. If your hearts set on something, go there, unless you know that it will be something that later won't look as great as you would like because of how the kitchen is used. For me, if I had a beadboard door, I would want to keep it either timber or painted dark, to help the look remain clean and classy, however if you want a fresh white or light toned paint colour, then go shaker. Only you will know what's best

Hopefully the doorway/walks are offset so that there isn't a direct line of sight from double doors through to toilet... Is there space at the foot of the bed for a small seating area? Lots of pics with this set up can be found on houzz to give you ideas. I would be inclined to move the bed towards the front windows and have a sitting area as the focus of anyone passing by.

I have Grey lapparto tiles in bathroom floor and side all and high gloss tiles on wall below window. A bit of gloss is good.