1) - good point, although I expect that BMW, Audi and others get pretty good pricing too based on both volume and relationship
2) - I don't think that is the case, since 3 production is only now expected to get to 5k/week in early 2018, with a yet undefined amount of additional capital required to get to 500k/yr.
3) - goes back to my original argument, that the "balance of car" is basically comparable to that of an ICE car, and Tesla is expecting to do that part cheaper. Yes, the drivetrain is simpler to manufacture. No doubt. But the seats, windows, doors, suspension, steering, etc. are not meaningfully different in EV vs. ICE. If you argue that the simplicity of assembling an EV drivetrain balances out the battery cost, then fair enough. The concern is the rest of the car. The suspension if anything might be more expensive due to battery weight, and everything else is comparable to an ICE. So how will Tesla make the balance of car for less than others, and make a bigger margin? Will point 1) be enough? Hopefully.