For the record, I was only offering my interpretation of Valavaern's intent, not advocating it. In fact, I partly rebutted it -- "leave Manaward alone, give RDM its own mitigation tool."
I mean of all casters, you'd think the one to get a damage barrier would be the one that constantly runs into most enemies' blood circles.

Not to undercut your point, but to my knowledge all of the jobs you listed except DRG and RDM have either Oh Shit buttons or mitigation effects of their own (DRG uniquely being the one to have personal vulnerability).