I also think it's better to try and retain a consistent position whilst cycling, unless cicrumstances dictate otherwise. Some of those cyclists were riding like it was a race. Too risky.. either ride in the cycle lane or ride primary - I would have chosen the latter due to the poor cycle lane design and the fact my speed would have been more in line with traffic flow. Plus, it would better deter the kind of atrocious driving you saw here..
Conext is good.