Another bunch of newbie question

[Jezter]

Disclaimer: please excuse my bad English and the sheer noobishness of my questions

First - what about blessings?
As it is seems to me from dom3 faq - as soon as i got a recent level in one of magic schools (F9 for example), a bunch of sacred units and a priest - all of these units will receive a fine bonus when blessed in battle by this priest. But this is a theory.
In practice i made a f9 pretender, chose Mictlan - and quickly made a group of jaguar warriors accompanied by a priest. According to faq al by sacred units will receive flaming weapon bonus as well as bonus attack - but nothing happened. Units received no new special ability in battle.
So - how do these blessings work? Do they work in my dominion only? Or everywhere i got a priest and sacreds? Do they work on common units (mean no the sacred ones)? And finally - is it worth it?
And another question. Many guides here advise to focus on crafting magical items for my commanders. I've been using zerg tactics in most of the games - just overrunning my enemies with tons of cannon fodder - with a little bit of mage\priest support - and found out that even the most stout enemy units\leaders fall very quickly to a zerg. My own commanders\pretender god also fall to a well-numbered army very quickly. So is it really worth it? Is it possible to make an overpowered commander\deity using craft items? And would he be able to survive the zerg?