And when you made the sacramental for one priest, the priest of a rival cult becomes envious and wants more for himslef, so you'll need to perpetually alter the balance depending on what the fort needs at the moment (and IMHO something to do to the player after the fort is running other than megaproject is really needed) and try to please one without angering too much the others. Highly religious followers of a neglected cult may become upset and cause much more fun than any angry god.
Or, you know, you just kill off everyone with an inconvenient or different religion, if we're going by how real life religions have done things.
I'm betting that would become a common option here as well. You could do that with actual gods as well, but they'll probably be a bit harder to kill. (but not impossible)
No, because when your, say, stonecraft god decides that all will make masterpieces for the next month, it'll be masterpiece mont no matter what. No additional choices on your side. And I can't help but feel that the thing between FlyingSpaghettiMonster and RaptorJesus is a little bit forced. Why should a god want a temple of another god instead of asking to make a better and larger one for himself?
What makes you assume that stonecraft god has the power to do that, or the desire to? And if it can make masterpieces itself, why have your dwarves make them? What does the god get out of it, that's worth their expenditure of power? And that could always be tweaked for balance and such. And with the gods actually existing, and being in the world and physical entities, I'd expect that they may act in more physical ways. I.E. why would a god of stone crafting, which seems itself a strongly physical thing, work in a more mystical indirect way of affecting how well other people craft stone, instead of just walking over to a boulder or a wall, and carving out a masterpiece for you directly? Perhaps a statue of itself for it's temple, especially if power comes from worship, or if it's just a rather vain or egocentric god. Gods should be people too, with their own personalities, and everything that goes along with that
And why wouldn't a god want the temple and perhaps followers of another god? They'd want it for the same reason they want it for themselves, I'd guess, whatever the reason for that is in the first place.
I think the right question to ask is, what do gods need? What do they want? If they don't want or need anything, then there's no point in them ever doing anything, or dwarves ever doing anything for them, and that isn't very interesting. And of course, if they have the power to do anything they want, then they don't need anything, so it's not very interesting to have gods that are absurdly overpowered.
This is not the same thing. An unimportant sphere of influence is unimportant since the beginning, so why the cult should come to the fort in the first place?
Regarded as unimportant doesn't necessarily mean it's always unimportant, and something that is important in one situation may not be so in another. A god that's primarily interested in warfare may not be very useful in times of peace, and a god that;s focused on weather may not be very useful when you live underground, etc. And people in real life follow gods that don't do anything at all, I'd imagine there would be people in dwarf fortress that follow gods that are simply less useful as well, for their own personal reasons.
And there would be benefits to following(hmm, supporting? following might not fit if they're not actually in a position of leadership, believing doesn't really fit, since it's obvious the god exists, and just because you believe it exists, doesn't mean you support it) a less powerful god, I mean, if your village is practically the only group that supports them, then they could always be around, and help out in small ways. A more powerful god, with the power to influence and assist, or lead, nations, probably won't take as much interest in doing as much for just a small village.
Also, a miracle is a miracle. How can the strenght of one's fait alter the effect of the miracle if we assume that the gods are phisical beings with actual power? Even if we say that the power of a god depends on the power of the faith of his followers, like what we see in many fantasy stories, when the god makes the miracle it means that he has been worshipped enough to grant him the power to do what he wants.
That's always one way to go about it,
http://tvtropes.org/pmwiki/pmwiki.php/Main/GodsNeedPrayerBadly http://tvtropes.org/pmwiki/pmwiki.php/Main/ClapYourHandsIfYouBelieve And it does provide a motavation for gods to actually do things.
As for having the power to do what they want, just because a god can do x, doesn't mean that they can do y. Heck, just because a god can do x, doesn't mean that they can do 2x (2x being bigger, or more often, or etc.).