Part of our problem here may be underlying assumptions in regards to how these things should be calculated. I've seen mention of a number of non-SRD feats that, of course, will boost damage out of proportion to the baseline. Here's a quote from a related thread that might help clarify some thoughts on the baseline itself.
Wulf Ratbane said:
I think that you can let WF, GWF, STR bonuses and such fall by the wayside-- they are meant to be incremental improvements over the baseline, so don't set the baseline to assume they're there.
If you just look at the percentages to hit over a range of 1 to 20 on the die roll (so we're only looking at the percentage of success and the numbers and AC don't matter), and calculate basic percentages of success, without even looking into damage, you come up with some approximate values for average damage based on the number of iterative attacks: 2 attacks = x1.5, 3 attacks = x1.8 and 4 attacks = x2.0 base average damage. With that, you can have any feats you want, and it still doesn't change what the percent of success is.
I have players that have a hard time adding up their bonuses, and they never write them down, so we have to add them up every time. Moving to non-iterative attacks works for me as a means of resolving that issue. Of course, if they can't add very well and remember it, then multiplying is out of the question. I am willing to make a few sacrifices to accomodate the simplification process. For the tendencies of my players and the feats I allow in game, the following including a list of my basic assumptions:
-There are no iterative attacks. If someone wants an extra attack, they can spend an action point to get it at a dramatically appropriate moment of their choosing.
-Two-weapon fighting still exists and both hands take the same penalty. (-8/-4, or -4/-2 with TWF). Fighting with more than one weapon is a full-round action.
-Characters and creatures add their BAB as bonus damage on non-natural attacks. Unarmed combat, such as a monk's unarmed attack, counts as a non-natural attack for these purposes. (Alternately, one could multiply the attacks damage by the x1.5, x1.8, and x2.0 numbers mentioned above, but I don't want the complications for my players.)
-2 x Str bonus to damage when wielding two-handed weapon; 1 x Str bonus damage for one-handed weapons.
-Creatures get the full range of natural attacks, but only as a full-round action. The primary attack is adjusted down by -5 (-2 with multiattack) to reflect the use of universally applied attack penalties.
-DR is kept the same. Yeah, it makes higher level characters more effective against creatures with DR, but I'm okay with that. (Alternately, one could multiply DR by the x1.5, x1.8, and x2.0 numbers mentioned above.)
-Sneak attacks and bonus weapon damage dice remain the same. (Alternately, one could up each d6 to d8 at +6 BAB, d10 at +11 BAB, and 2d6 at +15 BAB; and up each d10 to 2d6 at +6 BAB, 2d8 at +11 BAB, and 2d10 at +16 BAB.)
My approach won't reproduce a high level barbarian raging with tons of feats that maximize his damage and all that, but I'm okay with that, because I may not run a 20th level barbarian with all those complications for quite some time.
Hope that helps,
Flynn