"Any chance a modern dimmer meant for LEDs would correct the tone when dimmed?" Unlikely. The multiple different colored LEDs used to create the light do not behave equally when dimmed. They are normally balanced at full intensity to create an apparent color temperature, but any change in brightness will throw the balancing off.

I only checked Lowe's and Home Depot online and in store and they had nothing like just replacement rings. It's possible that there are so many different sizes and manufacturers that it would be impossible. I did not check at the electrical supply stores. I agree to the wisdom of keeping future options open by preserving the originals, but I've already started the process. My thinking is if it really looks bad with the Rustoleum Universal brushed nickel, I could just paint them while again. Worst case (costly) would be to change out all the recessed lights, but I hope it doesn't come to that. I've put a coat of Uma bonder on them after scuffing them up a bit with fine steel wool. My next step is elevating them with coins on cardboard and applying a thin coat in one direction. When it dries, I'll spray another thin coat up and down and then a third on a diagonal. Hoping for the best, not even going to think of the worst!

What about just using dimmable compact fluorescents? They make a flood-type attractive bulb to use in places where the bulb shows (like in a recessed light) and the bulbs only cost around $10.

Definitely pendant. Pendant lighting adds a lot of character and can accent the space very well. But usually use a lower wattage bulb because you don't want lights blasting in your eyes if it is an exposed bulb :) Unless you get pendants that only direct the light downward. Here are examples of exposed and downward lighting that have recessed lighting around them.