@FuzboleroXV

1. You wrote:
I am in the middle of exploring the practicalities of separating my public activities across 3 axis:

a) #personal / #professional
b) #identity (association) / #topics
c) #interests / #projects

My understanding of it is that:
a) is based on dichotomy between exogenic and endogenic motivations (your wage labour and your unpaid contribution to the society).
b) is based on dichotomy between self-classification and common goals (affinity?) as community-building criteria.
c) is (probably, I do not really understand it) built on dichotomy between absorbing information and using information to influence the environment.

In my perception, the model you assume is an individual, mapping oneself relatively to various external "landmarks", compartmentalizing oneself.

In this context I would prefer different perspective:

I am me. Apart from security purposes, I wish to be known as an integrated entity, because various aspects of my personality are interconnected and influence every my behaviour in every context.
If I engage in any interaction, my counterpart is a community (n>=2, -> infinity) [sorry, lack of math chars here].
Now, all diversity of life can be simply modelled through the ways those communities are built and (self-)governed. My "aspects" emerge naturally, in community contexts. Can be perceived separately or together, depending on community rules (open, closed, secret) with possible personal modifiers (if I exclude my posts within open community from being published in my main stream).
Also, following/being followed models nicely in this context, if we assume read-only or write-only roles in a community.
How about this approach?