[2019] The new spell AoE cluster above witch doesn't seem to work with righteous fire despite it having the spell tag. Is this intentional?

Those passives, both the AoE for spell skills, and the AoE conditional on killing things recently, do apply to Righteous Fire. It's hard to notice, espesciually if you have other area modifiers which they'll stack additively with, but they do make it larger - just not by a huge amount.