If you wanna get a scope of what modern SFF court intrigue is up to I'd recommend reading A Memory Called Empire and The Goblin Emperor. Very different vibes but both really imaginative.
Also just take inspiration from actual history that interests you. Try to find some unique angle or thematic...
Death of the Author by Nnedi Okorafor (great read so far), a now incomplete (thanks Jeff) and on sale omnibus of the first three Area X novels, The Terraformers by Annalee Newitz, and We are Satelites by Sarah Pinsker
I am inclined to agree with you, but I think there are a few big exceptions, though I can't think of too many of the top of my head. As you mentioned mainstream authors, G.R.R.M. is in my opinion at his best when introducing characters to cultures they're unfamiliar to. The Daenerys chapters in...
I'd argue it's impossible not to. I like looking into some strange weather phenomenon so I can later build it into the mythology.
You can do bad research and get away with it, but I'd encourage not to (even though I'm guilty of it myself). It's a lot more fun if you know what's going on and your...
The villain could be born into a position of power and lose it all in a matter of seconds, maybe his fall was even orchestrated by the protagonist. That could be a good driving force behind seemingly evil schemes. Revenge is an age old plot device that created some of the most iconic stories...