Snowsister, I am certainly not scared of H. We don't argue very often, but when we do it is about petty things when both under pressure. I think last one was about picking DS up from PILs. We both had work to do for a deadline that day and we both assumed that the other would go and get DS (lack of communication on both sides). Cue an argument 10 minutes before pick-up time. I went passive-aggressive, he swore. Not a big deal, if it was not for the swearing.
I think he does it because he has a bit of a temper and because he saw his parents interact in exactly the same way - to this day PILs have exchanges which I would call abusive, but it seems to work for them, so it is none of my business. For years DH did not think they loved each other at all because of the way they spoke to each other. I tend to see the softer side of them a lot more than he does. I think in that way he is similar to formerdiva's DH, and, as much as I can understand why he swears at me, it is still no excuse and it needs to stop.
In that sense, I am obviously more likely to agree with formerdiva's inferred opinion of my H (as in, ultimately caring but carrying around some baggage from watching his parents scream at each other throughout his childhood and beyond), than with cogito's (as in, callous uncaring bastard, who does not care about my feelings).
It is perfectly possible that I am experiencing cognitive dissonance wrt H and that he is in fact an uncaring fuckwit, who hurts me on purpose. I would not be the first one to fool myself. If I really believed that, however, I would not have any interest in trying to enter into power games and ultimatums, I would be packing mine and DS's bags. Not having a similar idea of what constitutes a caring relationship would be a deal-breaker. What would be the point of staying with someone who is cruel, even if I could force him to change his behaviour? However, based on previous experience, when asked specifically to stop certain behaviours because they were hurting me, H always would. I just need to communicate these requests very clearly, which is why this thread was so helpful in thinking them through.
I suppose that is the disappointing part for me of the whole sorry saga. Why does a grown, intelligent and otherwise sensitive man need pointing out that telling his wife to fuck herself is not on?
Still, I did point it out to him. I did not send the e-mail, but we talked and cleared the air a bit. He understood that for me the swearing was not a minor annoyance, which one could put up with because it is insignificant, but a major sign of disrespect, which I would not tolerate. In that respect, doctordwt's suggestions for what to say really helped me to reconnect with my feelings. Thank you.
In fact, many thanks to everyone who took the time to post and sorry for this rather verbose response. This thread really helped me work through my feelings 
.