Low slope, so considered flat for most codes, can’t use shingles. Basically every commercial roof has rocks, but In the last decade they’ve shifted to a vinyl. Lighter, handles more snow load.
3a-4a according to Canadian hardiness which takes into account a few more factors, but there’s also microclimates. Some communities are totally fine to grow peppers and gourds/squashes.
Everyone goes pee, but if you do it 30 times a day, it’s time to see a doctor.