Hi
Please test first if he can swallow by trying just a tenth (0.1 ml) of a small syringe and only give more if that has gone down. Adjust how little you give in one go to how well he can swallow in the coming days and be very careful that it goes down before you give more; avoid filling his mouth (0.3 ml) if he struggles to swallow.
Yes, support should step in but not if he is unable to process and if in doubt, please rather wait while his airways are still clearing. It is a very delicate balance to strike between two vital needs.
The respiratory sounds are from the intubation (oxygen supply during GA) and are nothing to worry about in terms of infection. They are not all that unusual for the first day after a procedure under anaesthetic. He's just bringing up any little fluid that has gone astray up his nose and down his bronchia but he would not have come home if his lungs weren't clear. You just don't want to risk more fluid getting into the airways if he struggles to swallow. Stroking a very ill piggy during feeding can trigger the chewing/swallowing process but you have to be very careful.
He can survive a day without food.