First, thanks for the breakdown. However, I think you are forgetting an important part of FnB in your analysis of chaotic resources and cataclysm. My understanding is FnB does 100% damage to your target but only 44% (I know thats not right but i think its close) damage to the other mobs in AoE range. That fact, at least in my mind, makes cataclysm better (dot it applies does 100% damage compared to the 44% from FnB on the mobs other than the main target
0than your breakdown mentions but also makes doing FnB chaos bolts (my assumption is 2 embers but hits everything but the CBs only do 44%