I did Dusy three years in row. "06 was 3 day...upper Dusy, layover dayhike, out. '07 was 2 day...lower Dusy, out. '08 was 3 day again...upper Dusy, layover dayhike, out. So I think that is a nice three day backpack with great view opportunities. Of course, I'd like to spend a longer time in just that area, but with the circumstances that I had limiting each trip, I was happy to have the time I did there.
As for over Kearsarge Pass, I would stay at Kearsarge Lakes, wander easy cross country down to Bullfrog Lake and possibly beyond that for a layover dayhike (trail back to camp,) then out the next day. (I stayed at Charlotte Lake for the first time in '08 and wished that we chosen Kearsarge instead. Charlotte is closer for the opportunity to go over Glen Pass, though, on your layover day.)
Ha, I looked back...way back...and on a 3 dayer in 1981 we did stay at Kearsarge Lakes and dayhiked over to Rae Lakes on the layover day. (We also drove overnight from SoCal to get to the TH.)