I'm not surprised you had the rage over the glasses. Ds3 is somewhat wild and feral at the moment.
Whilst some of it is his personality, I also think a great deal of his undesirable behaviour is learnt from ds2. Ds2's behaviour is mostly fab, but ds3 always picks up on small bits of the awful behaviour. We have had hitting and attempted biting from ds3 - mostly directed at ds2 when they are playing 'rough games', and Lordy they are rough with each other.
It's a difficult one because for so long we have told M to be careful and gentle with I. But I can really hold his own now, and is almost dominating M in rough games. Mostly because M doesn't retaliate, he just defends himself. I'm not saying I want M to beat the crap out of I, I just wish he would grab him and tell him 'no', instead of retreating.
I is good at saying sorry, but I really don't think he comprehends what it means, he's just learnt to say it after he's done something he shouldn't.
So, no I don't have any words of wisdom, but I do hear you Ali 