Jeremy,
I would refer to:
ASCE 8-02 Specification for the Design of Cold-Formed Stainless Steel Structural Members
http://www.asce.org/Product.aspx?ID=2147487569&ProductID=181341642
The clearance between glass and frame depends on the window product you are using. Some window systems have more clerance than other. I would suggets consulting with a window manufacturer to find out the exact clearances.
Just out of curiosity, what is the inter-story drift you are using for...