Upon putting up the first wall today, it makes me think that my roof is just way too tall. I'm going to leave the kitchen as the tall room. I like the idea of having one room with a dramatic, open feel; it seems like the kitchen could benefit most from this, as it is a standing area and could use a lot of good, old-fashioned, natural light.
This desire for a lower roof has led me to drop mostly the entire roof by 2 feet (aside from the kitchen, and the bedrooms - the bedroom ceiling dropping just 6"). I am now planning to use traditional 8-foot studs, whereas I had designed the walls with 10-footers (hence, the two-foot drop). This will result in the house sitting a little lower to the ground - a little more settled and relaxed of a feel. It will additionally result in a lower heating bill, and a great reduction in the amount of materials I will need (fewer courses of strawbales, shorter posts, less plaster, etc...).
With this drop, I've altered the form of the roof. The kitchen now has its own shed roof that stands tall above the rest. It's a slightly more dramatic, modern aesthetic.
Old roof design:
New roof design: