My question of "How far do I want to take it?" was answered on Saturday when the nickel plating process took much longer than I wanted. I found that it worked very well over existing, albeit worn down, nickel, using sulfuric acid as activator - no issues with adherence.
What I did find, though, is that I could not re-use the green solution for more than 3-4 keys without starting to see the black streaks. I also found that the famous plating "wand" started to disintegrate and I had to snip parts of it off. The manual warned about oxidation and removing it with a file or wire brush. They weren't kidding. I'll be making myself a new wand soon. I did rinse each piece in distilled water after the acid dip before plating.
As a result, I ran out of the solution 1/2 way through the process, so I'll order another 8oz. I basically just re-plated the keys that really needed it and left others alone. And forget the posts, I'm not touching those. Too much work cleaning up, and they don't see any finger traffic anyway.
Overall, it's definitely an improvement over what I started with. When working with fresh solution, the result looks exactly how I wanted it to look. Thanks again to John for the tip on the ultrasonic cleaner - I picked one up in Harbor Freight for 30 bucks.