What are the critical loads for doors in an unpressurized airplane?

When the airplane has no side slip, the pressure difference between the two sides of a door is pretty small, especially for our slow experimental LSA. With side slip it will increase, but how can we estimate this pressure difference?

Another critical load is the "bang" in abusive closing of a door. (The 172 I flew needed a big bang to lock, I hated it and did not understand why some designers would design like that.) Again I am pretty clueless in putting a numerical value to this load.

Any other loads should be considered?