Are there any other weapon points on the warbird other than the front (which seems to be a disruptor, a torpedo tube, and a navigational deflector). I've seen it shoot a phaser out of the hollow section once in TNG, but other than that, the ship's only ever shown to have one cannon, despite its enormous size. The Norexan class in Nemesis has had bolts coming from five locations, which is the most interesting action i've seen from the romulans so far.
Hmm I can't specifically recall seeing it fire from anywhere else. I'm certain it would be able to fire from other locations given its lack of manouevrability. Games have certainly invented other firing locations but whether its based on any kind of canon I'm not sure.