Always try to keep one thing in mind when detailing, and that's to try to use the *least* aggressive method possible to attain your goal. That being said, #83 is pretty much one of the most aggressive steps you can take to remove defects. If your car is in very good condition (no matter the age), and you really don't need to remove any defects, then I would say not to use it. You can use a much milder polish and bring back your like new shine again without having to be quite so aggressive.
Of course, you can use anything you want. If you just want to see what #83 will do to your car's finish, by all means, try it out. The only way to learn to try things out and learn from trial and error. You definitely can't *hurt* anything, so it's perfectly fine to experiment.
If you don't feel you need #83 quite yet, your list of products looks very good and if you want to try out #83, then just substitute #82 for #83 and try it.
