I feel like you perfectly expressed feelings and thoughts that I have had for all of my adult life vis a vis rejection, self-esteem, and the fear and avoidance of forming new social relations.
The insight that any action one might purposefully take towards anyone else might result in that person feeling bad and/or that a vindictive rejection is necessary for them to maintain their feeling of safety and sanity is something I found especially meaningful. It is my belief that no one has any right to expect another person to resist expressing any particular feeling they might feel. This belief combined with my desire not to court feeling like a monster in the eyes of someone who seems interesting to me has essentially paralyzed me socially all my life.
I can only really talk easily to strangers in formalized relationships like service workers or coworkers for whim a certain amount of empathy is demanded by the setting we find ourselves in. However, put me in a room with a bunch of people I don’t know at a social gathering and all I will feel is 'some of these people seem interesting and I want to talk to them, however if I do they’ll be completely justified if they feel creeped out bu my approach and act on that feeling by actively avoiding me or openly calling me a creepy weirdo for daring to open my mouth toward them. The fear of this experience of rejection is strong and well supported by all the sad tales I’ve read of people being creeped out by ehat if consider normal behavior.
I’m not the type to wholly dismiss the subjective experience of others just because their experience is unfavorable to me, however it is my observation that there’s no force left in social dynamics that can legitimately call on people to be polite or empathetic under perceived duress. Without a baseline expectation of empathy from others and/or support from the social setting if someone fails at empathy in public only the boldest and most carefree can risk the backlash they might come from threatening another person’s comfort, even inadvertently.
The only choice that seems to allow me to avoid the risk of feeling like a monster in the eyes of someone I don’t know well is to avoid actively engaging with such people as much as possible. I can’t fathom how anyone who has ever met a random stranger and engaged them in conversation is not considered a monster in hindsight by rusty person and other people generally. The mentality that talking to strangers and risking hurting their feelings or disturbing them is ever an acceptable thing to do seems like it should be a mark of shame and derision among those who rail against structural social patterns that perpetuate bad feelings in others over time.