Definitely grease all the rubber gaskets! When you assemble it back, make sure you torque the screws properly or equally and put them back like putting your bolts on your tire rims after you rotate them.........criss-cross! Don't overdo your torque.....you'll know it if you do koz the gaskets will bulge out!
My ROOs all pass a 10ATM test by my watchsmith after I greased them, I actually dived with my Safari up to 75-80ft last Feb!
Good luck!