When we discussed what could "intuitively" be expected, I only
considered decent, simple, 19th-century electrostatics, with
physical objects that exist in everyday life!
With a mass-zero sphere (and mass-less charge carriers as well)
things might start to escape our range of intuition.. I would
not be sure whether the pull of gravity will actually change the
direction of field lines, for instance, if the system is hovering
in a constant gravity field. The problem is that, even if the
equivalence principle allows us to use that frame, I do not know
how Maxwell's equations might change in a non-inertial frame. (It
probably can be looked up on Wikipedia, but intuitively I would
just expect the unexpected.)
For safety, I would go back to the original frame, where we know
Maxwell, and try to solve it there. But the combination of E-
and B-fields and moving charges make this complicated of course.
The precise shape of the field is not obvious to begin with, and
since you ask whether some things might be precisely "cancelled",
you would really need precise information!
Alternatively, we can work in the sphere's own stationary frame
and *assume* that Maxwell is unaltered for electrostatics in a
gravity field. In that case your proposed solution with uniform
charge does not seem to be stable. There is an upward pull of the
E-field on the charge carriers (which have no mass so they are
not pulled down by gravity) and there must be a downward pull of
gravity on the E-field energy density around the sphere (which
contains all the mass now). So intuitively we might still expect
the charge to move off centre (upwards) and the E-field lines to
be drooping downwards.. but the latter is incompatible with the
starting assumption that electrostatics is unaltered by gravity.
(So probably it isn't!)