That's already the problem. Don't enter the intersection if you can not speedily finish your turn. There is also already another ped on collision course the moment they start moving forward.
Immaterial. I don't want self driving cars driving like Bostonians or worse, New yorkers. Self driving cars need to follow the law, drive defensively, and be conservative. If that means that they take 10 additional minutes to get to their destination so what? The alternative is that the car kills someone because of impatience, that is to say an improperly weighted time value function, which I would think no one wants.