For audio circuits, I use unity-gain stable op-amps, so if I'm not mistaken, the C across R2 is not required to prevent oscillation, right? I've never used one before, and so far (knock on fiberglass substrate) everything works fine. If I'm being naive, say so. (I have started adding RF-blocking C filters on the input, though.)
Yes to oscillations. I think if the gain is more than 1, you should always have a cap
across R2. Also, as mentioned, it makes a good low-pass filter too.