the design you are working with, would increase coning angle simply because of the elbow length. you will need drag and lead hinges because it doesnt matter that the cofg and centre of mast is in line. what matters is the angle from the mast of each blade.
teetering heads are different because the head is tilting on the mast causing the moments you talked about earlier between mast and head. the blades DONT change there angle from the spinning axis on teeter heads theorfore no lead and lag can be present. i think the wear marks on the robinsons lu talks about are from start up (shuddering belts) and maybe hooks joint moments absorbed at the hub.
p.s. if some body can explain that the head and blade tips are not always parrallel on a teetering head, my coments are not true.
