Not the best picture but it could be the coating on the display MacBook have a film on them i believe it's for anti reflection, anyway that coating can rub off, check if those dots are still on when the display is off if they are then it's that most likely.
if it the transformer (most likely is) its a VERY dangerous repair and you could get shocked and die but if you re careful its over 100-200 dollars for a new transformer not worth it in my opinion since a new microwave is only $300 USD
most likely a fried dongle or damaged try seeing the warranty on it if not could just buy a new one, if you want to open it tho its REALLY hard not to break it, btw $20 on razers website for a new one.
Depending it could be the usb c port or the battery my friend had the same problem and he was told it was fried, also Nintendo has fixing services maybe call them and see. good luck