False, you cannot buy a Model 3, or any Tesla for that matter that doesn't have leather. There was a planed cloth seat for the model 3 but they scrapped that.
Is it real animal skin? As someone who opts out of leather interiors in cars, and knowing that Tesla sells well to the SV crowd, I'm surprised that there'd be no way to buy a tesla without killing some cattle.
Yes, polyurethane, which according to testing, performs better than real leather in the rubbing/scratching tests. Durability in general is superior on actual 'premium' leatherette/vegan leather offerings.
Sure, you can make crap leatherette material that is way too hot and sticky and feels like cheap vinyl, but that's not what this is.