So, you didn't comment on the second of my ponderables: can Moose live with direct access to state as hash elements of $self?

Hm. The simple answer is: I don't know.

The more thoughtful answer is, if I am not going to use the generated accessors; and I see no use for the introspection, what would I get from Moose?

It cannot generate my non-accessor methods for me, so nothing to gain there.

And one of Moose' strongest features is that it will inter-operate, subclass and superclass, bog standard blessed ref classes. So, I don't need to use Moose in order to benefit from existing moose-based modules.

At that point, your ponderable becomes a moot issue. (For me.)