What you are describing is not a maintenance issue, it is a symptom of a problem. Call for a repairman, your refrig is under warranty.
I will watch and see if it happens again.
Yeah.
It sounds as if the cooling element is not cycling. They need to cycle — go off for a while and then come back on. If they are on constantly, that causes the ice build-up, and the ice build-up blocks the air flow.
Air conditioners have a similar problem, especially on really hot days. They, too, need to cycle.
Exactly. The only maintenance there should be to a fridge is wiping the finger prints off the outside and a periodic cleaning on the inside.