I agree with much of what you stated, though I main BLM I did try SMN on T10-12 for utility purposes and found it just rather abysmal. Honestly I think the numbers, as you said, are fine in terms of SMN vs. BLM but it just really ruins the flow of the SMN as a job to have to worry so much about your mana. Aetherflowing on CD as part of your rotation is one thing, but having to energy drain just feels "bad" when Fester is a much more desirable option. If SE refuses to budge on moving caster/ranged DPS numbers to be more in line with melee (and I don't mind melee doing "more" but design more fights where ranged won't always be outclassed by melee) then at the very least keep SMN numbers the same and just make them a little more mana efficient somehow.