Pass protection schemes out of gun four wide

Do you run shallow crossers?
Do you have a slide built into your protection?
Do you use sink to swivel concepts?

Coach, it would appear to me you have a decision to make as to what you want to do. Does your philosophy incorporate protecting the QB at all costs, or does it entail letting the QB become his own best blocker (as mine does out of an empty gun) and have him run out of trouble while throwing on the run?
The suggestions offered above are all very sound.
Myself, I like the idea of the swing man. The correct way to utilize and keep him in the pattern is to check release him. If you want bodies on bodies, then Coach Campbell's way is the best, imo, and really he can check release as well off the line. I like your OC's way, because he is basically using the swing route as a screen type pass (let the defense come with their ears laid back and then just hit the swing as the QB retreats and sucks them out of position). Just my opinion.

Coach Easton

Sink to swivel is basically a double read idea for the gcg with an a gap player. If there is an a gap player, the center determines who takes him, either the center or the guard, then the guard or center that does not take the a gap player sinks behind the other guy and then head on a swivel looking to linebacker either side, then to outside for blitz alerts