Does the system really display as "00000"? That seems like an odd design choice, I'd have thought just a single "0" would be far more legible in this scenario, especially if it's on a 7-segment display.
I don't think passengers would have noticed this as anything other than a regular takeoff, because ATC does request slow climbs (ie. slower rate of ascent) every now and then.
What’s wonderful too is that the abbreviations are often based on non English words as well, so they aren’t intuitive. As an example, instead of typing “mist” in a METAR it is “BR” based on the French word brume.
When there are 50 pilots on the radio and things are moving fast there isn’t time to slow down and spell things out, and doing so can actually be more dangerous when extraneous stuff ends up on the radio and is misinterpreted.
It looks like the aircraft didn't leave the runway until the runway safety area at the end. That is something any passenger looking out the window could notice. A normal takeoff has the aircraft leaving the runway well before the end.
I don't think so, because the departure was at 3:10AM local time (23:10Z). It would have been too dark to perceive.