I have no idea on the shark, so many sharks are protected now you have to be careful if you keep one.
No question it's a mangrove/gray snapper & a nice one, the bigger ones I have caught offshore always seem to have that bronze color although I have caught some inshore like that too. A lot of people in the gulf call them black snapper, not to be confused with the actual black snapper!
I have never heard a mangrove being called a schoolmaster, but that wouldn't suprise me. Red Porgy's are often called white snapper. The Schoolmaster's we spear on the reefs in the bahamas have a yellow tail & yellow fins. I believe those are actual schoolmaster snapper.
I took some pictures of a huge cubera I saw snorkling a few weeks ago, the teeth are a dead give away. I'll try to post if they come out.
Hard to see b/c used a cell phone but the fish in the bottom right corner is the biggest/fattest mangrove I have caught, we also had a problem with the ice that day: