What do you think about adding shutters to the front of the house?

A porch would add curb appeal and be much more inviting.

Here are some pictures of the same house! I know you have a different style home, but this just gives you and idea of what a porch can do!!

Please no shutters. especially to the big long windows.

You have a dutch colonial - if you add a second level over the sunroom addition, one connection to the upper story of the garage could be made with connecting decks. . . you can build a french door or french door slider in a dormer on the back yard side of the garage and design the new second level area with a deck area to the back and have them engineer some structure so the decks can connect together - yes, officially, you will have to walk outside, but it will be outside upstairs on a deck which you can organize a nice canvas awning cover for . .

No shutters for this style home, though you can do window boxes if you are so inclined . . . perhaps consider painting your stormdoor / front door a deep charcoal to echo the roof . . or dark wine red . .

Shutters for the four left windows, an awning over the door, and larger foundation plantings. I'd do limelight or incrediball hydrangeas on the right, in front of the line of windows, and bright rhododendrons flanking the door. Do boxwoods between on each side, and then plant something small and colorful (begonias or geraniums, perhaps?) in front of those.

I agree with the previous comments. You have a lot of horizontal lines on a flat surface with no breaks. Some vertical plant accents at the edges of the main part of the house would help to accent the central part of the house. A porch would help bring the front door forward so it seems less flat. The long windows are tough as is the long gutter line. I would bring the garden out from the house in front of the long window with multiple layers in a curve to make the windows feel further back as you approach. You can have some higher plants in front of the right part of the window with successively smaller bushes curving around those. I can't tell what is happening with the roof but that is expensive to change, Also, a small issue but your front door lights look very low. Get nice big ones and raise them to the proper height.

the only way I see the roofs being able to connect properly is to extend the gambrel (barn) roof out over the sunroom to that edge right edge of the house. Then the barn roof from the garage could tie back into the rake/gable end wall that you create by extending the roof over. Not sure if it could actually work out- hard to tell from the photos.