What's the house look like? Were it me, 3/4", NO contour and 6/6, 12/12 is too busy for me and I don't care for the contour grids.

6/6 will be perfect.

I can see the house on my phone but not here. 6-over-6 with the narrowest width grid available.

If you look at antique windows in my area, as the the number of lights decreased, they also made the muntins narrower. The windows in the 1830s house I lived in (6/6) had much narrower muntins than the houses from pre-1800 (8/8, 12/12)

Another vote for 6 over 6.

Here is some info on shutters.

https://www.lifeofanarchitect.com/residential-architecture-101-shutters/

And I'd consider replacing the white railing with black metal to go better with your architecture.

Your house is based on this style, so shutters are appropriate, but to be properly sized, they would have to touch or almost touch or overlap the corners , and historically this was considered okay because they were used. So maybe your house would look better without them.

This also shows that the windows were not perfectly spaced, which was not uncommon.

The house that I lived had windows that were slightly narrower (as well as shorter) as you went up, in order to make the house look a little taller and more graceful. So on that house the margin between the shutters got slightly wider.

6/6 sounds good but get the narrow grids. All old windows had narrow grids to maximize glass area

Since you are going to all this work I agree the shutters need to be larger or just gone. I know grids are what is usually done for the windows in this style of house but maybe just on the top of the winow not all the way and yes to narrow grids and IMO the ones thta could be removed if you wanted to down the road . I think no shutters and a more saturated siding color and maybe just wider window trim in white . While you are at this get rid of that silly arched window top

yes our side windows also have the half moons over then so we will be keeping that in the front as well