Do you know what sort of an airplane it was?
Cabin doors are usually of the plug type, so extremely unlikely of opening in flight.
The screaming sounds unnecessary, although, the Passenger Address system on this aircraft may have been put into a maximum volume mode automatically by the deployment of masks. Real decompressions may result in a lot of extra noise and this has to be compensated for, but, from your description, it doesn't sound like there was a real decompression. Also, most aircraft are fitted with automatic emergency decompression announcements. Ours are loud, and speak in a "commanding", not screaming voice. However, manual deployment may not trigger the announcements on this aircraft type.
I don't know why the lights went off. On the aircraft I'm familiar with, the lights should go full bright.
Oxygen mask deployment should not generate lots of dust and cobwebs, but again, this could be aircraft specific
The compartments for holding the masks should be dust free, otherwise this might generate a fire.
There is insufficient information to comment on the airmanship. Rapid descents, however, would make things rather busy in the cockpit. You will be descending rapidly through various flight levels where other aircraft may be, so you need to communicate your intentions to Air Traffic Control as well as communicate with the passengers and crew. The flight crew may have chosen to stick to their formal company training/procedures rather than make a polite, long-winded announcement of their intentions (for the sake of safety).
Unfortunately, despite their training,
cabin crew sometimes do react like normal human beings. This is another reason why you should listen to the safety briefings and read the safety card, not your newspaper
"Do as I say, rather than do as I do".
Anyway, an official report has to be made after such events. Eventually the full details will surface in the public domain.
Rgds