Due respect to OBD (and a few others), while the approach may have looked standard going on altitude loss alone, the DFDR data shows that for much of the way down from 1000 RA, the energy state of the aircraft was in constant flux.
From the data, it appears the FO seemed to be on GS safari. He began low, passing the target and ended up high for the remainder of time he had the aircraft.
On another note, the late flap change, while not critical, despite being contrary to SWA SOP (and most sane operators I would imagine), was part of the ever changing milieu of parameters and targets that never seemed to settle in.
I don't get the part about why the landing attitude of nose down: as I've never flown a 737, what explains landing nose low
The aircraft was not really nose low until just before touchdown and that was caused by a lack of back pressure during what little flare there was.