I'm more apt to forget to turn the flashers off. I think this is just as hazardous as forgetting to put them on. Most people just see the blinker they want to see. After I get through thinking , "Man, what an A-hole move by that guy " I turn them off. Shocked they don't have a beeping sound reminding you they are on. Which they may in a few, but not in mine.
As far as the handbrake on the automatics, it is still necessary, but some of the ole timers will tighten the crap out of them. Once every few months they cover it in a PCM with the broken handbrake in the middle of the group. Always makes me chuckle.