I still say people complaining about this is using their turn signals wrong. Instead of locking the turn signal in place, just hold it halfway down. It isn't rocket science to hold it in place while signaling to change lanes for those that feel they need to have undivided attention to barely nudge the wheel.The turn signal / indicator control takes a bit of getting used to. I found myself activating the opposite direction a few times when trying to stop the indicator. Getting out of the vehicle without a "power off" button seems odd. At the moment, I use the iPhone app to activate "vehicle lock" after getting out, but I wish there was a more positive way to just push something to say "shut the car off" and have it lock the doors when I close them. I am probably missing something in the correct procedure to leave the car, but just passing along first impressions here.
The car turns itself off like like any Tesla (don't know about Roadster since that is what you drive). Just make sure in the screen settings that walk away lock is set (I believe it is by default).