Re: Is there a list of characters Marvel has the rights to?
Okay, what matters is that a character has a significant role in one or more properties.
For instance, Marvel can use the Skrulls because they're related to the Hulk, but they're also important to the Fantastic Four. Super Skrull is solely related to the Fantastic Four so Marvel can't use him.
Mutants who lack decades of history with The Avengers can't join the MCU. That means that Wolverine, Storm, Rogue and Havok are still with Fox alone. The only exception other than Quicksilver and SW is Beast but Marvel can't call him a mutant which is so integral to his identity that he'll probably never be part of the MCU.
Ronan is part of the MCU. I'd suspect that the Kree as a race are also as well. That said, I can imagine that Ronan can also pop up in the Fantastic Four films down the line but most named Kree from the comics (Quasar, Wraith, Magnitron, Supreme Intelligence, etc) can't because Marvel owns the rights to Guardians of the Galaxy, Inhumans and Ms. Marvel so much like Beast, it's not worth it to include him.
Sony shares rights with Marvel over Kingpin since he's part of both Spider-Man and Daredevil rights.
Fox has a loophole whereby they can use all properties related to X-Men and Fantastic Four. This means that Captain Britain, Alpha Flight, Starjammers and Silver Surfer spin-offs are a possibility.
I'm not sure where the rights to the Brood lie but they're probably shared as they're both tied to the X-Men and Ms. Marvel.
I have no idea which Shi'Ar characters belong to which studio. They're tied to Ms. Marve, Avengers and Guardians but Fox could also sue claiming that they're part of the X-Men or Fantastic Four rights and they'd have a point. That's the one property that I'm the least sure about.