Sorry it is sideways. I will play with the image and flip it shortly. Gotta go to carpool right now though!

It's coming along nicely! A few things to consider:
Making the pitch of the three front gables smaller. They look close to or about the same pitch as the whole roof, and traditionally gables are a shallower pitch. This would also make them easier to roof and save a few pennies on materials. Also not too keen on the little roofing return on the gable over the door. I would also think about making the columns a couple of inches larger in diameter, and when installing them remember to line up the top of the shaft (not capital) of the column with the frieze/architrave(horizontal beam) above, which I also think could be a little more substantial. Also, traditional round columns taper either from the base or starting from about 1/3 up the base, with the top of the shaft being about 5/6 of the diameter of the base of the shaft. I do like the shutters, but remember to size them as if they would cover the window when closed, even if inoperable. The windows without shutters I would consider making a few inches wider if you can spare the wall space, or adding shutters to these as well. Love the traditional sidelight and fanlight glazing patterns, but would try to get them in a true half-elliptical shape with a stilt to look authentic.

I would say simplify the roofline. Make the front facing gables a lower pitch than the main room and consider not having all rooflines hipped.

The eave returns on the gables should be almost flat pitch on the top, not an exaggerated pitch as shown.

I don't think there would be a pent-style return eave going across the main pediment of the house.

The Doric porch pillars are not in the right position. They should actually extend beyond the frieze and architrave rather than having that overhang them on the sides and front. You should really consider doing a whole entablature with a pedimented front.

Don't use shutters on the double windows, they obviously can't cover the window if closed. I agree that you should try to get elliptical or arched windows that are "stilted": this means the Glass is a true half arch or ellipse, so the frame will be slightly more than a half arch or ellipse.

I would consider trying a variation with quoins only on the most outside corner of the house.

I would consider keystoning only the arched windows and using a plain lintel on the flat topped windows. A keystone is really only structural in an arch.

Since you look like you are going for authenticity I strongly recommend the following book:

Get Your House Right by Marianne Cusato & Ben Pentreath

Here is a link that might be useful: Get Your House Right