Not even. A single Uber car is shared between multiple users during a single day, even if they ride alone. Uber Pool is even more efficient in that regard, of course. Tesla cars just sit in garages or parking waiting for their owner to have a need for them.
Yes, but this is better wear than parking wear when it doesn't serve anyone. Sure, individual vehicles last longer but it takes costly real estate on curbs, parkings and garages and still costs a bunch. I'd still bet fewer constantly running vehicles are better for the environment than many occasionally used vehicles, including for commute. The sheer difference of number of trips - around 2 per day for a commuter car compared to around 8 per day in March 2020 before the lockdown for taxis is eating smaller offsets.
Not as much as the relationship density suggests, I'd wager. Unlike other web giants who actively expect worldwide traffic except when they are barred from operating (then they cooperate with the local government to pass along user data), Uber only expects traffic from locations where it is enabled, reducing the overall infrastructure needs.