[It's a concern that's well-founded; with so much power, they could raze whole cities with barely a flick of their wrist. And had. Her eyes dim somewhat at the memory for a moment, but she shakes it away, refocusing her attention on the matter at hand.]

Only those limits imposed upon them by the field of alchemy itself: equivalent exchange. You can't make something out of nothing. If you wanted to create a weapon from stone, you would need to use an equivalent amount of stone from some area nearby.

[Ah, right:]

There are three rules imposed upon State Alchemists by the military itself, though those are sometimes still broken by alchemists gone rogue.

[She feels safe sharing this much; it's information freely available in Amestris, after all.]