Primary stiffener removed..
That is not the normal footwell size, and yes, there is a primary fuselage stiffener removed. The secondary stiffeners in the floorpan are displaced when adding footwells. I would actually say those would make entry/exit more difficult, as the flat area is gone that you can step on. The standard footwell is simply a V shape, some have a small flat on the bottom. The key to watch for, as the FWD slope has to clear the aileron pushtube at full deflection. Without being critical of the photo you posted, I would say there is some loss of floor strength in that design. I'm not able to post pics at the moment, but if you PM me, I may be able to send you some via Email.
8A7 / Advance NC