Good to hear the de humidifier is doing its job.
There should be no problems with your dabbing technique, I have used it to cover lighter areas caused by my laziness when sanding out glue spots 😜
As for drying/curing between coats if it isn't tackcy to the touch, go for it.
The dreaded debris... I get it all the time.. dust and cat thing hair is the bane of my life....
What I do is very gently rub it with 320 grit between coats.
I only rub in one direction so as not to remove too much finish.
This removes the crud and gives a better tooth for the next coat as well as helping to keep the finish flat.