LazySageDao
I don't think its strange author that you combined Star Wars in this Wizarding World universe. After all the plot takes place in one galaxy. In the Legends continuous arcs, the Force doesn't really extend much to the entire Universe. It only reside to this galaxy where the setting of Star Wars take place. There was this beings called Yuuzha Vong that derives from another galaxy that didn't possessed the Force. They invaded the SW galaxy years later after the Empire were defeated. So having Star Wars in the Wizarding World won't be out of the place. Beside the Force could be just settled as some sort of a subtype category of magic.
I think author should focus on the original theory of catastrophic event happened in the past. A plot where older gods cast enchantment on solar system which will erode mana of earth over a period of time and this MC need to escape solar system and then travel to different worlds to gain their knowledge and power up enough to counter the hidden villains