hello
YEP normal.
Formula can be very high in Iron - and when the excess iron (not needed by bub) is excreted through the poo - it is a green colour... hence green poo!

As for stuffy noses - babies will get them on and off all year. Unless he is having trouble breathing or high fever , i wouldnt be too concerned. YOu can drip a few drops of saline in his nostrils to help soften the hard snotties and make it easier for him to breathe

HTH