Rian Johnson and Kathleen Kennedy.
So.... save it from what, exactly?
You refer to the treatment of Mark Hamill being something abominable, but I'm not sure what exactly you mean. Only thing I can think of is when he said that he disagreed with the direction Luke's story was taken - which we know is actually a plot point George Lucas came up with, not Johnson or Kennedy - and he later went back on that anyways
Not so. In fact, it's done pretty much as expected for a sequel released so soon after its predecessor
Attack of the Clones made approx. 64.9% of the income The Phantom Menace did (~$649 million to just over $1 billion)
The Last Jedi grossed slightly higher, at about 66.5% of The Force Awakens ($1.33 billion compared to just over $2 billion)
The Empire Strikes Back made 70.6% of the profits of A New Hope/Star Wars ($547 million compared to $775 million, unadjusted for inflation)
It's a historical trend with pretty much every single trilogy or series of movies released in relatively quick succession, and SW is no exception. A sequel almost invariably grosses less than its predecessor, not that it won't make an impressive profit, of course, with something as big as SW
Hell, if you compare TLJ to Rogue One, it made 133% as much, though Anthology and Saga films are different entities with different marketing approaches