India Blue with no patterning is Wild Type. IB with the pattern added would be IBBS for Black Shoulder, IB Pied for Pied, IBSP for Silver Pied, etc. Not all splits to colors or patterns are visual but there are normally clues. I see no clues on your chick.
I can see no white on him to indicate any white genes, you would have to spread his wings for closer inspection. A Dark Pied doesn't have to have any white on them but you could tell from the parents if that was the case. He looks to be a typical Wild Type.
If you only turn one out at a time, 'they' won't all wander off. That doesn't mean you don't have to watch them, it takes a little effort to be a good steward.
We put ours on the ground by 12 weeks with no heat. They will be fine as long as they have a coop to go into at night. Leave a light on in the coop to draw them inside at night.
The season is basically over. Any eggs that are laid from now on out I will leave for the hens to set if they want. After two weeks I will toss the old eggs out or boil them for the chicks to eat.
Can you ask your vet for preloaded syringes of Tylan 200? You need about five with 1.0ml and give one shot SQ daily for five days. Yes, if there is a lot of face swelling I would press the infection out.
If a sinus infection is left too long the pus will harden and need to be cut out but I think what you are dealing with is an infection caused by a thorny sticker that got lodged in the cheek. When expressing the pus use one finger or thumb inside the mouth and press with the opposing finger...