[captain]

Bart,
Let's keep it simple. A ladder is two parrallel beams [round or box]and some cross members. Superformance's 2x4 box beams are constructed to start parrallel, angle in, then out to direct force outward in a front or rear accident. This minimizes the force through the chassis and shock to the occupants.
As far as safety of the FF5, just look at the points of attachment of the roll bar. The inner forward tube is welded to a tab! This should be a structural beam. Diameter of the tube wont matter if it is not securely mounted to a chassis.
Outlaw is in Huntington ,NY. You can ask them how many FF5 they built but they have a heck of a race shop. Ask the owner for suggested improvements to a FF5 kit.
If you want to build a Cobra, G-d Bless. Start with an ERA. Otherwise, accept the fact "you get what you pay for".