Hubble orbit?

The subject of STS-125 and the Hubble's orbit came up on another group.
I misremembered it being in an equatorial orbit when of course (duh) it
was launched into the same inclination as the 28.5-deg latitude of the
Cape. But this got me to wondering why they didn't put Hubble in an
equatorial orbit, considering the possible benefits of less complicated
celestial tracking and orbital issues such as precession. Was the
28.5-deg orbit chosen mainly because the Shuttle doesn't have the fuel
capacity to do an equatorial dog-leg maneuver, even with the assist of
the OMS during the launch phase, with a payload as massive as Hubble?
Could the Shuttle have used the OMS engines to make an orbital plane
change from a temporary 28.5-deg orbit into an equatorial one before
releasing the Hubble? Perhaps the answer is they would have if they
could have.