2. Arizona doesn't always have nice weather. Haboobs, fog during the winter mornings/nights, monsoon season with heavy rain and hail. There are plenty of weather conditions in Arizona. And if building the visual recognition is the easy part, what is the hard part?
3. Fair, but that is already something their parent company does as another business; Maps/Earth. There is nothing to suggest they CAN'T do this on roads they haven't seen before, but it's obviously far safer to do this on roads they know.
4. They partnered with Daimler to make self driving trucks who couldn't use Uber to move shipments. They aren't competing with Uber necessarily.
As for Tesla, there is nothing to suggest they are doing it the right way. They have had numerous self driving failures.