Regarding exiting a group, I think this must be a universal right, but not timed so as to escape an acceptable punishment for an offence (the meaning of "acceptable" here is in need of crafting, and the boundary would surely be fuzzy). The analogy here is emigration, only not necessarily geographical in nature.

Regarding corporations and taxes, as you say, this is already a problem; non-geographical (or fine-grained geographical) law does not change anything essential. (As for corporations, there is no reason to regard them as having rights in the first place, which provides considerable latitude for applying restrictive laws.)

Regarding castes, freedom of exit makes an enormous difference. Membership in a restrictive group would be optional, reversible, and not necessarily hereditary.
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The alternative, it seems to me, is to pit groups seeking order and decency (by their standards) against those seeking a different sort of order and decency. Or, to put it concretely, indigenous peoples (e.g., those of Europe) have more reason to fear immigrants if those immigrants may eventually establish noxious laws that are universally applicable throughout their ancestral homeland. They would have less reason to fear if groups could get most of what they want without forcing it on others.

Note that the world is becoming saturated with surveillance systems, and that this will change possibilities for law enforcement in relevant ways. In particular, it will likely make restrictions more effective and potentially personalised. All the more reason to be able to opt out of other people's offencive notions of right and wrong -- and to opt into a context that enforces one's own enlightened standards.

Words and ideas I offer here may be used freely and without attribution.