My advice to you specifically would be a few things...
1 - If you have raiders that can't be even remotely self-aware (can't switch, avoid obvious things, correctly handle mechanics) then they need to be replaced.
2 - Delegate some of the calling to other officers, having just 1 person call everything is to stressful.
3 - Have officers for each roll (ranged, melee, tank, healer) that members can receive advise from if there failing, these players should have good knowledge of every class in there respective roll.
4 - If you cannot handle your own play while raid leading then simply do not raid lead.... I am one of the callers in my own guild and am still perfectly able to keep up my own rotation.
If you have all this setup and members still fail to be pulling decent numbers/correctly do the tactic then simply warn them... Tell them if they don't pull there finger out, do the research, practice on a dummy/dungeons and get that stuff sorted by next raid they will be replaced.