Advice in using Mesa 2 90 power amp

Hi fellas,

Just picked up a used Mesa 2:90 stereo power amp to try with my Kemper through my Matamp 2X12. Got a couple of quick questions.

Is the monitor/main outputs from the kemper line level (as the mesa has a switch at the input for instrument or line level). I'm guessing it must be line level?

The Matamp 2x12 cab has got two Vintage 30's in it, rated at 60w each I think. If the volume of the Mesa wasn't cranked, would it be OK to use the cab in a stereo configuration even though each speaker would only be rated at 60w each?

Thanks Doc.