I'm sure you already made up your mind about heat pumps and that I can't convince you otherwise. But for other readers, let me add some thoughts to your points.

1) well, there's a grid. So as long as someone somewhere on your continent produces green energy it is viable and green.

2) arguable. Depends on your legislation.

3) Again, there's a grid. And even considering the worst case of no renewable sources at all: A heat pump (which uses 1kWh of electricity to provide 3-6kWh of heat) powered by a diesel generator is still more efficient than burning the diesel directly. Now add efficient combined cycle power plants, wind, biomass, hydro and battery storage systems...