I haven't waded through every post in this thread, but I've looked at most, so forgive me if this is redundant.
I don't think much of these types of discussions should revolve around bow weight to begin with. I've yet to see a bow kill an animal. I've seen a lot of arrows kill animals, but not bows.
To that end, I believe the discussion should center around what arrow weight driving what broadhead, needs to be thrown at what speed, and at what distances the arrow stays at or above that speed.
Working backward from there, a person can determine what bow will do the job adequately for them by testing it.
Because a bow is not a bow is not a bow, a person would have to determine if their bow will get the job done or not. It could be that one man's X pound bow, drawn to 29 inches shoots a ??? grain arrow as fast or faster than another persons X + 10 pound selfbow drawn to 27 inches.
As far as what arrow/speed combination is effective I would suggest looking at what CONSISTENTLY gets the job done for the animal you are hunting. For me consistently factors in what happens IF...fill in the blank (I dead center a rib on impact, I hit a shoulder blade, I gut shoot the animal, the animal drops and I hit the spine, etc.)
After you get that worked out and are confident in your setup, GO HUNT! If something doesn't work out for you, re-evaluate and fix what ails you.
Stan