The Haste variable (constant) only increases your number of attacks, and as a result decreases the delay of your weapon accordingly. Whatever your damage output as a result of the haste varies of course.
Second, Damage Bonus is not added to the Damage variable of the weapon. So if you are level 28 and you have a damage bonus of 1, wielding a 9/18 weapon... the damage bonus does not make it a 10/18 weapon. Damage Bonus applies to the amount of damage you have done as a result of a hit.
Now for a rough comparison of weapons, while considering damage bonus, refer to this chart here lucy.fnord.net/dmgbonus.html and then plug that variable into this formula:
((DMG * 2) + DMG Bonus) / Delay
Bear in mind this doesn't include procs or anything. It's strictly melee damage comparison. Hopefully, this can help you decide whether a weapon is worth wielding or not.