Reading forums on here is like deja-vu. I will tell you why I pass on right side when turning left:
Some people forget to go when arrow is green or will crawl through the intersection at 10Km/hr. Those arrows don't last long. When you got hot food items that need to get out, I don't dilly-dally through the lights. I won't be waiting for the straight thru traffic or the next green. Pick up the pace, people! ;)
As for signalling: FWC (first world compaint). Everyone has forgotten at some point even "US GOOD DRIVERS".
I am yet to see any serious injuries or deaths due to mistakes made within the city's speed limit. Even being sideswiped or bumped is not fatal. Funny how everything looks so dramatic to some people. (not naming you, but I have seen other posts where people say "it's only a matter of time before we see a fatality".)
Defensive driving is key. (Anticipate errors from others). Learn that and you will be accident free.
Just my take. I have been wrong before
Have a good day.