i frequently have to carry design documents,...
i frequently have to carry design documents, which are 11x17 inches. will a 2 inch binder fit in the main compartment?
Not a problem! I usually fit a 1" binder, a pair of shoes, toiletries, a weekend's worth of clothes and a 15.4" laptop.
A laptop and a 2" 11 x 17 binder may be a little cramped at the very bottom of the bag (it tapers a little bit) but I still think it will fit fine.