Thank you! I wrote them precisely to be system agnostic, in case people want to use them for their D&D style games. I almost included a conversion between Rank and HD, but thought that would be better left to the game master.
I think so. Less is more when it comes to hacking, sometimes. I was thinking I could adapt a lot of your ideas to a Traveller/Mazerats game, or to an Over the Edge 2e game. Especially in the setting of OTE, 2e — the idea of some people collecting demons on a rather odd, corrupt, island (Al Amarja) that is the home of the dissolute, depraved, desperate and potentially deranged strikes me as something worth following up. One day.