A better concept, though perhaps Gray is not the right term.
Usually being "Gray" implies that they dabble in both sides of the Force... which is ridiculous. Riding the thin line of morality is a no-no in Star Wars... unless you intend to eventually tip over to evilness fully at some point. A popular Gray Jedi would be Kyle Katarn, flinging around lightning without being a Darkie.
I prefer 'Renegade' for your above defintion. Qui-Gon Jinn was definitely a Renegade, rather than a potentially evil man. Sure, he didn't mess with the whole political aspect of things, but he was still a do-gooder. ✅
As for Potentium... also bleh.