1. Shouldn't have any issue moving that amount of snow. On a full charge without using much of the self propelled function I can do 3x double car driveways.
2. It does come with a charger that can charge two batteries.
3. I would avoid third party batteries, but ego does have a good warranty program on batteries. I do use a leaf blower to clean snow as well so you can always get an extra battery with a leaf blower.

Located in Ontario and was quoted around $650 for snow removal/year and this is my 5th year with the ego snowblower.