[Taqwus]

Regarding Iron Faith, I don't think it lets you pick a non-Drain dominion. Lousy research is the one huge downside of choosing Iron Faith; you must find a library for the sages if you want to be remotely competitive in research.

Regarding the weaknesses regarding the reliance on armor, fear the magic -- especially air magic, as /all/ lightning attacks are armor-negating, and orb lightning isn't that hard to research and scales with the mage's air power. A Pythium Arch Theurg with a Communicant swarm can toss out lightning like nobody's business, for instance.