The interim report has given a lot of points for discussion on info that was not available.
But I give below answers (as much as I know) for some of the questions raised by various, though some are irrelevant to this thread.
Land with locked wheels and no anti-skid?
Prior to landing brakes are selected on through the auto brake system. Pilot selects the deceleration rate depending on aircraft weight, runway length available, dry/wet condition etc. But the brakes are not applied till the air/gnd sensing circuit has sensed that the aircraft weight has come on wheels. The anti-skid system also plays a part in keeping the brakes released on most aircraft till that time. This is true on all aircraft from B747 on wards.
Was the battery switched off on purpose or did was it drained in just the 53 seconds?
The recording is actually of some one turning off the Main battery switch in the cockpit. It was probably done by the engineer to de-power the aircraft completely as there was a fire in one zone. Such action is normal.
The fact that the APU shutdown because a battery had failed seems odd
On most aircraft I know, APU fire protection is through the APU battery. So it could be same here, (I have not seen the WDM for this plane). You do not want to run an APU on ground without the fire protection. Do you?
Is there no smoke/fire alarm in the E/E compartment ? Do we have smoke alarms in each readily accessible aircraft toilet, but not in inaccessible compartments full of high energy technical devices ?
This aircraft and most Boeing types are fitted with a smoke detector in the duct that carries the cooling air out of the electronics bay. That way all the electronic boxes etc are monitored. It is like fitting a smoke alarm near the exhaust fan of a room than any one location inside the room. These equipment are force cooled, so this arrangement is possible.