Any receiver can drive a pair of M80's. A lot will depend on your listening distance determined by room and its size and how loud you like to listen to music and movies. If you don't push the receiver to hard then you won't run into problems, push it hard and for a long period you can risk it overheating.
In terms of the crossover points they will be different from speaker to speaker, brand to brand based on the measured T/S parameters of the woofers and tweeters that is used in the design. Specific measurements are taken on drivers such as frequency response, impedance and cumulative spectral decay (waterfall plots) to find the break up/resonances of the specific drivers in question. You want to avoid this and this is where the crossover design and the selection of the crossover points are important. Crossing over the midrange lower depends on the driver parameters and where the driver begins to "break up".
