[wrvond]

I’ve never had a problem running those two items at the same time. It seems to me that the microwave and air conditioner are the items most often reported as too much to run together. The heater only uses 12 vdc so should not affect a 120 vac coffee maker.
Water in the window tracks should not happen either. Though I imagine it’s possible on a sideways opening window if the wind is blowing the right direction.