O.k., this is a excellent question!
If you run 33s on your stock factory wheels, then the larger tires will not have any negative effect on ball joint wear. The reason is, because you are keeping the centerline of the tire, in the same proximity of the mounting hub flange. So your ball joints really don't care, because the weight distribution on each side of them, hasn't changed!
So as long as the tire is in balance, then it will have no negative effect.
With this set up, you may get a slight rub on tight turns. But running 95% on roads, you should be good to go!
What you have been reading about, is when adding wheel spacers, or changing the backspacing, (moving the wheel, and tire out further), now you have changed the geometry, and added addition stress to the ball joints, and wheel hub bearings. The ball joints are a weak link to start with, partially due to the fact, that they don't have any grease fittings. So yes, the added stress, will accelerate the wear factor.
You have a excellent set up with a 4.10 ration, and a 6 speed, plus 33s!
So keep your stock wheels, install your 33s, and enjoy your ride......