Alderaan: No worries. 😃
In the 1975 second draft, the Emperor is definitely a figurehead There are several references to the real power behind the throne: a “Sith Master” named Prince Espaa Valorum, who’s also Vader’s boss and lives in the Imperial base on the Cloud City of Alderaan.
In the third draft, this character seems to have been dropped entirely: the crawl refers to Vader as “the right hand of the Emperor” instead of Prince Valorum, whose name is never mentioned at all.
At this point I imagine Lucas saw Vader’s relationship with the Emperor as a fraught partnership, with each of them working to undermine the other. As I said above, it’s likely this dynamic was Zahn’s model for Thrawn & C’Baoth.
The idea of the Emperor being a Sith sorcerer - and thus unquestionably Vader’s superior - only came about during the writing of ESB.