Setup for Crabbing - Advice needed

...The bait bags D mentioned work ok but sometimes I stuff them too much and the clasp breaks but they are cheap and it lets the pots fold easier.

When the clasps break just use tie-wraps.  They don't even have to be tight, and you can cut them with your fishing pliers. 

Those Promar traps look very, very light and delicate, so one would need to fill them with rocks or rebar. 

I've also found that trying to use some sort of handheld reel to pull up the traps is a fools errand.  Pull up the trap by hand, let the line lay in the water or pool in your lap (I let it trail in the water), and when the trap is up, then use the reel to wind up the line.   

Pull up the trap by hand, let the line lay in the water or pool in your lap (I let it trail in the water), and when the trap is up, then use the reel to wind up the line.   

+1

Definitely by hand.  Using the scotty pulley thing is good too, but not needed.  Key thing here is, leave the line in the water.  If you drop your trap by accident, line in your lap could result in you being pulled overboard.  If the line is in the water and you drop your trap, all you have to do is pull it back up again.