As a general rule, can you install publically released versions of iOS after installing a beta release? As a general rule, can you install publically released versions of iOS (earlier versions than the beta) after installing a beta release?
I just asked a question regarding this and managed to figure out that it is possible. If you enter recovery mode you can force restore the device and iTunes will update it to the most recent public release for that device. See my question here: Can I undo the upgrade to iOS 7 by restoring to iOS 6.1.3?

So in conclusion, yes, I'd say as a general rule it is currently confirmed possible under current circumstances and software releases possible to downgrade back to the publicly approved version of iOS.