Not DF'd here, never joined.
Is disfellowshipping a superior form of correction? I think of the example of an addict. It is certainly counterproductive to the addict's recovery to be cut off from his entire social network. I would NEVER turn in a JW addict to the judicial process.
Do some congregation members deliberately sabotage their status as a way to exit? I'd think these people had exited mentally some time ago. I'm thinking of the examples I've heard here of spouses who will commit adultery in order to "release" their partner to remarry.
Are disaffected members allowed to walk away? I think the annual shepherding visits are case in point that there is no quiet exit allowed. A member under scrutiny MUST state if they believe the Faithful and Discreet Slave. What is the point of a JC six years after a member has left? What possible positive outcome can there be from such action?
Being the social creatures we are, the disfellowshipped need a social outlet somewhere. Case in point members like Mad or Fred Hathaway, who are "true believers" AND social outcasts. They come here to have SOMEONE to talk to. We can't help it, this is the way human beings are built.
In the scenario you provided, BR25, a "true believing" disfellowshipped would likely NOT post here. They would either remain alone in their misery, or be busy working on reinstatement.