I cycle commuted through London for 9 years luckily with only 1 minor accident, i think as long as you ride assertively, take up the lane when necessary and move into position for turning nice and early then generally you will get by ok. I also tried to avoid being on the inside of any high sided vehicle like the plague… 20 seconds off my day is way better than a ride in an ambulance. That’s not to say i didn’t have my fair share of near misses when either a) i was being a nob ( i learned to ride a little slower and improve my positioning to be safer) or b) buses / addison lee were being complete to$$ers.
If you think london is bad, you should try Sydney. I have been here 3 months and have been sideswiped, sworn at and nearly taken out at roundabouts (whilst on them and other cars flying onto them). Also half of sydney roads seem to be at least 3 lanes wide and full of double length articulated lorries. Proper scary…