To answer a few questions.

Don Muang still operates. We were out in Rangsit last week, directly beside the old airport, and planes were taking off. It's used for Charters and private aircraft, and perfectly usable.

Unfortunately, all the equipment is said to have been moved over to the new BKK, so moving commercial flights back would still be a chore.

As for your arriving flights this week. You can expect.

Delays landing, not unlike holding patterns in many other parts of the world. Long taxi in to the Airport. And a probability of a bus gate.

I'd think there are no safety concerns that sould worry you for an arriving flight.