Regarding Daemon Blackfyre and the first Blackfyre Rebellion: you give Daemon and his inner circle a lot of credit; if Daemon had won the Rebellion, what kind of King would he have been? Could he appease his supporters? What happens to Dorne?

Definitely a more warlike King, to be certain, and he’d probably be kept busy quelling rebellions and bringing the whole of the realm under his reign. 

As I’ve said, I think his main way of appeasing his supporters would have been to redistribute titles and the land that came with them – the Reynes would have been given Casterly Rock, if the Lothstons had stayed loyal he’d probably give them the Lord Paramouncy, maybe the Carons get Storm’s End, there’s any number of candidates for Highgarden (including the Tyrells), etc. 

Depending on his level of success at capturing the royal family, war with Dorne probably would have followed. However, the major difference probably would have been that Daemon I would have had the support of House Yronwood and its vassals, which means an quick sweep down the Boneway and a quick march along the coast (Richard Lionheart-style) to Sunspear. Secondly, I think Daemon would have made the Yronwoods Princes of Dorne, as a way to divide and rule.