If 2nd job Blue Mage what weapon/role

[Radacci]

Snip

those numbers don't say much, except that tank is doing little more than half the dps of a monk.
ofc tank can do good numbers when you have help from nin/drg/mch/ast, vit food+pots, and whatever else boosts your damage output, and killing stuff quickly, before dps numbers drop to much.
ofc tanks need some damage capacity, or they would be useless as OT.
i don't think anyone is suggesting that BLU tank would learn only def skills.
currently tanks have 1 high impact atk, each, that doesn't make them strong jobs....you're tank, so you shouldn't even be strong, or you'd be OP as F*** and there'd be no reason to play as DPS jobs.
as you said, you're fine; no more, no less.