I only skimmed through the text as I am at uni atm, but I got the feel the biggest problems you are having are people not showing up, slow progression and people venting/disrespecting you.

My advice: if raiding is no longer fun, then don't do it. It's not supposed to be a huge chore at the end of the day. I wouldn't wprry about your dps: at this point of gearing, it's down to your dps players underperforming or you guys pulling the mobs ineffectively, but I doubt your dps is to blame. Personally I would compare the dps numbers with other similar comps, and see if you can do bigger pulls somehow or use healer aggro to pack groups up.