My daughter gets her L's this year. I've been slowly educating her for years about driving. She knows full and well now that the biggest thing for anyone to have on the road is experience to know what other dumbasses are going to do. You almost have to assume every other driver is a complete dumbass as you can then predict people making dumb moves. I've said to her numerous times, "hey I bet this or that will happen" and guess what, almost every time I'm right.
As you say defensive driving is what its all about. I'm a fairly aggressive driver, which you can be if you have your wits about you and can foresee potential collisions about to occur. Unfortunately there are a lot that are aggressive and have no idea how to actually drive.
When my daughter was learning she wrote off a car, wasn't her fault. Driving on the Maroondah Hwy a car on the left (I wasn't there, my partner was teaching her) looked like it might come out in front of her, nope, it came out and tried to do a U turn to go the other way, and started the U turn as my daughter was going past. Sometimes even the best drivers can't anticipate the level of stupidity out there. The cop who attended the accident said my daughter's actions, as a learner, likely saved my partner's legs as she did manage to evade as much as she could and had looked ahead to make sure there was nothing coming the other way.
As you say, you can teach them this to some extent by pointing to cars and predicting what they are likely to do. I drove trams many years ago, if you don't anticipate what the cars are going to do when you are driving 40 tonnes with no steering you will hit things, a lot of things. My tram driving teacher would point to cars and tell me what she thought they would do. She was mostly right but occasionally someone would do something so stupid you just couldn't anticipate it. The best one I remember was a car overtaking my tram on the right hand side, ie: the other side of the road, on Hawthorn Rd (1 lane in each direction and lots of small streets entering, this is so dangerous). But, the moron was not very observant, there was a police car right behind them who promptly hit the lights and sirens to give them a fine.
I am very good at reading traffic because I was taught to read traffic. You will do well if you can pass some of this on. I always assume every other driver is an idiot and is about to do something stupid.
I find most drivers intensely annoying: no planning ahead, no awareness, act as if they are the only one on the road etc. There really are a hell of a lot of terrible drivers out there.
DS