Your tip #2 seems contrary to my primary advice to them: make decent burgers. Those two-dimensional, shoe-leather pucks they serve up now are disgusting.
I'd buy several a week at that price, as compared to the last time I ate a McD's burger which was about 2003.
But they'd need to strip down their whole system and the menu to what Five Guys has today, which is about the same as what McDonalds had in 1960.