Dragons are little of all of it: They started out as beasts , that were tamed, and then began to be bred for intelligence ( and size, both large and small- some rich lady wanted a lap dragon of course). Most are 'controlled' with magic. They've got a variety of intelligence levels, so magical collars are more about 'spacial awareness for the less intelligent ones. Human-intelligence dragons are deemed a kind of 'citizen'.
I would say yes there are nations that are rising up currently. The city of 'Kirag' is one such region ( where the game would be based/ is based).
Slavery? Its not restricted to color or ethnicity, but is based based around... something else. People started created 'Slave lines' for particular duties, but magically reinforcing them. (So the rich and powerful got 'more fancy', while the slaves got more 'practical'). It got hammered about 200 years ago, so its more 'classism', in Napoleonic dress than anything. People pinging you for your heritage mostly: Got a lot of courtesan slave-blood in (and so look extra gorgeous?) Someone's probably gonna remark on it, and might try to peg for work as a Courtesan, not that its wrong to use it, but its sterotpying to the extreme.
Plenty of Industry relating to dragons. (Dragons are measured in Feet), so the Largest is about fifteen foot tall and 30ft long, (wing spans vary, if they are flying-varities, the utmost would likely be around 160ft.) If not, Wings are gonna be all over the map. (small, non fuctional ect).
Noblity is 'earned', its a meritocracy, as is Royalty ( its a combination, the Divine Right, comes from specical Oracles and confirmation via sacred objects. Each House has one. So becoming Peerage, says: You have some that Oracles have seen worthy.