I think you 2 are on the same side so lets focus on the issues with RDM and not each other...
I agree that making Temper a AoE spell that would stack with COR could add a lot of appeal to invite a RDM.
However, I disagree with adding sphere effects to RDM. I only say this because I would rather see AoE spells for RDM so it can support both DD and mages and be a support job on the same level as COR,BRD and SMN instead of being forced to pick whether to support DD or mages.