Set half the film in Santa Prisca? I think that would be amazing
Making Bane the benevolent dictator of his island home would be great way to continue the themes of TDK. Batman busts up some Santa Priscan smuggling operations in Gotham, which upsets the SP economy and the fragile balance between warring militias, industrial factions and cartels. This makes Batman a problem for Bane.
Bane is what Batman would be if Bruce had the balls to take all-out control of Gotham city. Bane runs a whole country in his iron grip; he laughs at Batman because he thinks he's weak, foolish and gutless. Bane therefore is the better protector, while Batman hides in shadows, meddles inefficiently, chases his own demons and wallows in blame and guilt like some kind of self-pitying martyr. Pathetic. A barely grown boy playing dress-ups in the night.
Things come to head when Batman, recklessly, travels to Santa Prisca to put a permanent end to operations that affect Gotham. Baaaad move. He sneaks in and out like a slithering rat. Bane on the other hand does not operate like that. When he finds out he travels to Gotham as an official head of state and demands the government hand over Batman. When they do not, or cannot, he has no other recourse but to take him down himself with his own highly trained men, his own plans and cunning, and finally his own two fists. This would be a great movie, and very different for Batman, which is what we need.