It doesn't really matter how you improve your balance- just that you do it. Besides, standing on one foot for two minutes in front of the TV can't kill you. And the best way to improve general flexibility is to stretch, daily. Daily stretching only takes about 15 minutes, and its side effects include reduced stress, lower occurrence of physical injury, and burned calories. Whatever stretching routine you choose, just make sure you try to reach a little further each day until you end up with the flexibility that you desire.
Strong wrists are key to a strong swing.
And it should be pretty easy to strengthen your wrists beyond their current strength. Two tools with which to do this are soup cans and hammers. Swinging a hammer, or doing wrist curls with soup cans, are easy methods of strengthening the wrists using household items, and in the comfort of your home too. Back problems plague older golfers. But ten minutes of crunches, sit-ups, or leg lifts every other day can strengthen those abs and reduce the chance of back injury.