Got different. R410 is a much higher pressure gas compared to the r32. So your technician need to be a bit more careful during installation.

Nice. Unless there are issues like gas leaks or etc, just do a filter cleaning every month would be suffice. If you have easy access to the outdoor compressor, just spray pipe water onto to the condenser every 6 months like that.

Sure can. Only use chemical if the outdoor unit is really2 dirty. Downside of using chemical treatment is that it can eat up the fins if the concentration is too much.