Regarding canon: I don't know the second series well. Certainly not well enough to GM in a world where it definitely happened. I'm not all that firm on the first series after Nine Princes, but I can fake that. So I'm dumping things like Ghostwheel, the sentient Pattern and the Keep of Four Worlds and characters like Coral and Jasra whose names I know but whose personality and history are just a vague blur to me. And, of course, as always, Corwin might have lied.
This game will aspire to "epic adventure". The stories will be about your characters overcoming their personal demons, and coming to grips with the relationships between them and the people important to them. But the way they'll be facing those demons and changing those relationships will often be through the all important tools of bravery, peril and desperate sword-fights on creaking rope bridges over active volcanoes.
Characters from well nigh any of the heroic genres will find a niche in this world. I can see immediate places for folks who act like broad-chested heroes of space opera science, gritty private investigators, swashbuckling pirates or soul-sick retired assassins. It would even be great fun to play somebody who is not yet a hero, but has the makings of greatness beneath their youthful exterior. Heck, you can even go into the game intending to be a villain, doing terrible things for your own twisted reasons, though I will insist that the reasons make ethical sense to the character. After all, most everybody considers themselves the hero of their own story.
What probably won't work too well is somebody who has no internal motivation towards greatness, someone who needs to be dragged into everything. As GM I honestly don't have the energy for that sort of characer.
So that's what the game is. There are an awful lot of things that it isn't. The game will not be a constant feel-good series of victories for the characters. An important part of winning a war will be learning to cope with losing a battle. I would be very surprised and disappointed if any character in the game could climb to greatness without suffering terrible setbacks along the way.
The game will not be a throne-war. If you would feel better with your character on the throne of Amber, please feel free to try to put her there. But know that the game does not end if that happens. You'll be bound to actually cope with the problems that leadership implies, which will probably be much harder than taking the throne ever was.
The game will not be an incestuous orgy to put Melrose Place to shame. I mean... really! I can hardly believe some of the stories that I hear from other Amber games. I am not against having the odd romance bloom over the course of several stories, but I refuse to have them force-grown under hot-house conditions just to please players who want to put the moves on everything around them. There will, specifically, definitely, NOT be anything described in the game that would be considered pornographic by a mild prude like myself.
In this game the important things (like romance, as I said) will happen by slow degrees. Please recognize that a five thousand mile long dragon of fire that swoops down intent on devouring Amber is not an important thing. That could happen without warning. An estranged father and son reconciling, that's important. And that will not happen all at once, it will happen by tiny fractions of grudging acceptance. If you try to force it to happen too quickly things will only get worse. I'm the GM, I really can guarantee that.