"However, 10,000 feet is the limit if APU supplied both bleeds and electric."
Do we have ANYTHING to suggest both or one engine generators were u/s before take-off? Why else would the APU be supplying 'electrics'? Was it dispatched with one gen?
"if not to check that pressurization is back to normal after bleed reconfiguration"
It should have been obvious if it had been done 'correctly' as the cabin altitude would probably start descending as both packs gave normal flow. No need to level off. To level off (at 16000ft or whatever) would be essential if the altitude horn had sounded, and should have been done when it did sound, followed by a descent.
"Wouldn’t they switch it to Manual"
That would be the normal drill having tried 'ALTN'
"The conversation lasted through 28,900 feet"
There is a huge gap here between what happened at 16000 ft and 28900ft. How long at 16? When were the various problems ("air conditioning, cabin lights and equipment cooling fans") reported to Maintrol?
"A failure of one or both APU busses"
It SHOULD be impossible to power both busses with the APU in a 300 in the air UNLESS the air/ground sensor is stuck in 'Ground' mode
"if one pack fails, loss of pressurization is possible"
No, it SHOULD be possible to climb to 33000ft and maintain normal cabin pressure.
"Failure of the outflow valve to close completely"
With battery power it should still work. Surely any significant electrical failure would be evident on the FDR? Which "cabin lights" were a problem? The whole topic of this 'reconstruction' is too vague for me. WHAT did they 'reconstruct' - and why?
A no-engine bleed take-off, no reconfiguration plus APU failure?
What parameters were used to 'reconstruct' the abnormal cabin pressure at 12000ft?
What were the defects it carried at dispatch regarding electrics and pressurisation?