Ok, have broken it down to look at each point:
lack of positive emotion/enthusiasm.
I feel very little emotion a lot of the time and am far more likely to react to what others would see as trivial things than major events. When I do feel emotion I often find it very hard to express it. It doesn't mean I never care or am happy about anything, just that there is often a barrier to my being able to do so.
inability to express himself/say how he feels at an appropriate time
I have this very strongly. It can range from being unable to say that I need to get a drink if we're somewhere unfamiliar, or even in town, to being unable to express if I'm unhappy or sad. It relates primarily to my difficulties with initiating I think. One of the best things that helps is for me to write things down.
lack of social skills
Now, I don't have this too badly in some ways. I can learn all the social niceties, "how are you," etc but may forget to say them. I won't lie of I don't like something and pretend I do, but I will find something about the thing I like and comment on that, rather than a generic "that looks great", unless I actually do think the thing looks great. Or I'll soften the criticism by makign it clear it's just my opinion. My social difficulties come more in obtaining and maintaining friendships offline, apart from DH I speak very little to other adults most of the time and even with DH spend a lot of time in silence if he doesn't talk first (doesn't mean I can never start the conversations off, just that it's not easy).
lack of interest in sex
Yes, very much so, although enjoyable once things get going and not bothered about the build up to the actual act. I'd be hypocritical to offer advice on this as I still flinch involuntarily and find face to face contact almost impossible to manage.
inability to accept responsibility for his behaviour
This is something that must be very difficult for you.
difficulty in controlling his anger and inability to stop ranting when angry and lack of memory of what he's said.
I have this, but am not - I hope - abusive. I find it very difficult to let go of a topic once I'm able to express how I feel about it. DH frequently has to tell me that I've been saying the same thing over and over. If your ex's anger spills over into violence and or other forms of abuse that that is unacceptable.
The main thing I can see with myself and with DH is that we both compromise. I make mistakes, he makes mistakes, but we both understand that the other one is not actively trying to be hurtful.