What is the damage over time formula?

[eqravenprince]

My best guess for damage formula for Primary Hand:
average damage = (weapon damage*2 + damagebonus)/2
damage over time = average damage / weapon delay

And offhand formula:
damage over time = (weapon damage/weapon delay)

Level 37 and damage bonus of 4

Primary Hand
Adamantite Club average damage = (15*2 + 4)/2 = 17
Adamantite Club damage over time = 17/25 = .68

Primary Hand
Stave of Shielding average damage = (17*2 + 4)/2 = 19
Stave of Shielding damage over time = 19/28 = .6785

Off Hand
Adamantite Club damage over time = 15/25 = .6

Off Hand
Stave of Shielding damage over time = 17/28 = .607

So level 37 and after Adamantite Club wins for best primary weapon and Stave of Shielding wins for best secondary weapon. I also assume that off hand fires off each time the delay timer ends. So damage would be accumulative .68 + .607 = 1.287.

What is the damage bonus for two handed weapons by level? I know my my Baton of Faith is is 2 at level 28. But my 1 handed weapons damage bonus is 1. Also my formula doesn't take into account random events such as procs and ripostes. Is there something I could add to my formula for ripostes and procs?