I am very interested in the sense of self topic, not necessarily from the exact points of view you are presenting. But the questions of how someone can detect that someone else has a problems with sense of self and what can be done to repair the self are very interesting to me.

Regarding DSM-5, there is the alternative personality disorders model that indeed assesses the level on functioning of the personality and based on this model, the issues with identity and interpersonal functioning is indeed central and all other specific behavioural symptoms are secondary. Using this model also enables to better capture currently sub-clinical cases - people who do not have enough particular symptoms but whose identity has still considerable disturbances. I started masters in psych this Fall and I'm hoping to do my master's thesis on this topic.

I also totally agree that in order heal or recover or start forming perhaps the first time in one's life a more coherent sense of self, there must be someone Other there who is trustworthy, reliable, patient and stable enough in their own self to offer themselves to be used for this purpose. I can say without any doubt that for me my T has been and continually is that Other. What I haven't fully understood is whether he fully understand what he is doing for me. Sometimes it seems to me that he indeed does know and he knows even better than me what he is offering to me. Some other times I'm doubting that he knows because what he is doing for me seems more than one could ever expect from anyone.

So, I hope that over time I will also figure out, what is his knowledge about what he is offering to me and where did he obtain this knowledge - is it something that stems from his personality and it's based on his intuition mostly or is it something he was trained at some point to do as well.