If you'd like some analysis from my perspective, at least, then I might try and address some of those.

The main thing is that the direction you're addressing this from is the other way round to how many trans people do. The "fundamental" or "intrinsic" component is various forms of disdain, misery, disgust, etc... that can be broadly associated with different situations. The decision to treat that disdain in terms of gender or sex tends to be what most people consider "realising they're trans". That analysis came after the acknowledgement of the sensations. After that, people tend to think about it more, and try and relate their experiences to that of others, and by doing so tend to more clearly associate "triggers" with the negative sensations. These tend to be sexual characteristics associated with their birth sex, the acknowledgement of those characteristics by others, social treatment in a way associated with their birth sex, etc... but there obviously isn't any fundamental reason why different trans people should interpret the feelings in the same way, and most of them don't. The specific rationalisation of why sexual characteristics might be considered a deformity is irrelevant in the actual analysis of the underlying phenomenon; what's relevant is the fact that many trans people experience a sensation comparable to disdain for a deformity.

Why does dysphoria require outside participation? Because a) it's triggered by outside behavior, and b) there haven't been any demonstrated ways of alleviating it without outside participation.