+1 on leaving it alone, with respect to upgrades.
If you want to spend money on it, refresh the suspension with factory parts (probably just the bushings at this point), and that car will feel magnificent. At 22k miles, it shouldn't need anything major. Make sure the oil's been changed, radiator's flushed, and brake fluid flushed, and changing the engine and cabin air filter would be nice things to do, too. If not mileage, then the amount of time passed makes those things essential to change. Diff and tranny fluids are coming up at 30k miles.
Maintenance if it's a 6-cylinder is the usual: water pump, radiator bits (neck, reservoir), various dead sensors, thermostat, and the rear shock mounts tend to die early, too. You can upgrade to something like the Rogue RSMs here.