It may take f/t, it may not; it may take rats, but I wouldn't hold my breath...doesn't hurt to try.

You can definitely feed it more often, though I wouldn't suggest letting it slam 3-4 mice a week right away. At that age, all the snake really needs is maintenance feeding to thrive- as long as it's not dreadfully thin. Maybe try to get it on an every other week feeding schedule to start, if it works for a while, try to bump it up to every 11-12 days or so. Good luck, nice to see you taking on an older snake...