Speaker/Microphone and Inverting Op Amp

Jiggy-Ninja

1) What is a typical voltage level coming from an 8Ω speaker being used as a microphone to record a human voice at average volume? I kept forgetting to bring it to school to measure it's output with the oscilloscope, so I'm wondering if anyone here knows it.

2) I seem to remember reading somewhere that using an inverting op amp configuration with a gain of less than 1 was unstable, or otherwise bad for some reason. I can't remember where I read it or why it said it was bad or anything else. This op amp would be used to attenuate an audio tone to a level manageable by the circuitry that formerly had the speaker hooked up to it (a Walkie-Talkie). Would there be any problems with this setup, or is my spotty memory unfounded?