That doesn't seem to be a breast blister, just general burning or irritation from wet or soiled litter. You did say these were new, so they could have been in not too good of conditions. And you are sure it's a silkie rooster, not a hen? The pattern looks like when a silkie hen has become broody and pulled out her chest and belly feathers to sit on eggs. If they won't roost, try a really short roost bar, and put them upon it for a few nights to get used to it. My silkies all roosted about 2-3 feet high because they were used to it, but they needed a lower bar to get up to it. If they won't roost, you will just have to make sure their litter is very soft and dry. Pine shavings stay pretty dry, compared to straw or hay. Also make sure there are no lice or mites irritating the skin.