The feed is simple starter feed for chicks.
They use the heat when they want, they come out when they feel its enough. The bulb is 15W, smallest that there is. I don't think that is a problem though but I will reduce the temperature still.
Poop looks fine now. I will take photos and send you after a while. The poop is normal solid, usually brown or dark brown.
Yes, there is no mucus or runny nose for now. This looks like hiccup but it is not going away. The chick sneezes as in this video:
Please watch carefully, he opens his mouth to breathe and then sneezes.