Nothing will affect the feel of your house as much as the quality of the light. If you can at all swing it, keep your divided lights. Looking at your photo, those windows are gorgeous. Can you place glass on the exterior? I have some lead light windows in 2 locations. I made new frames with the leaded old glass on the inside and plain glass on the outside. While not as weather-tight, it's much better than single glass. While not as neat as your present windows, the new windows that have the interior and exterior lights with the spacers between the glass also look great and are at the present standards for energy efficient. We live in the PNW and used Milgard; less expensive than Anderson and Marvin, but so far I'm very happy with them.

I think the white trim gives it a much more contemporary look. It's more work to have it done in a different color, but the overall look is cleaner.

I understand wanting to keep the views from as many rooms as possible. However, how much time is spent in the bedrooms? And is the view visible the majority of time one spends in the bedroom? Consider that the most restful, secure sleep is obtained when the bed is placed opposite the entry door. That is not possible in any of your current bedroom layouts. Perhaps you should consider single solid glass French doors or windows flanking the beds opposite the doors rather than the large windows you show on the plan. Choice of doors or windows would be based on accessibility to a deck. I assume bedroom 1 and the office/bedroom have built-in bunk beds. I think the deck between the family and bedroom 3 seems inaccessible and a bit of a waste, and I wonder how one gets outside from the kitchen with the trash, etc. Do you have no plans to garage the vehicles?

First, find out if the hallway wall is load bearing. If it is, you probably won't be allowed to cut into it or remove it without a structural engineer approving the modification(s). Are solar tube skylights an option? Translucent glass doors might give a little bit more light into the hallway...