2. Multiple frames misinterpreting something the same way doesn't help you. Also many times you can only draw 1 conclusion from many frames e.g you need N seconds to tell a person's intent.
3. Redundant sensors are great. Radar + camera can help give good estimation about where things are in the world, but cameras have disadvantages (e.g occlusion, low sun angle, etc) and radar too (resolution, poor range, interference, etc). If you don't have redundancies for the weakness of each sensor, you are going to have problems in the long tail.
4. Ghost mode driving doesn't actually capture the long tail of crazy situations, especially since their current sensors most certainly don't store all the data needed to recreate the world. You need to drive a verrryyy long time to see some real-world situations that break your assumptions about your sensor robustness.
5. Highway autopilot is more or less solved (with varying safety bars). Surface streets are the hard part and Tesla hasn't demonstrated any progress there beyond PR / hype.