Though I do not own RMX, and most likely won’t buy it, it appears that RMX is your best option. Other than that, using pre-generated characters (and a wide rang of them for versatility), limiting player options (races, professions, backgrounds, which as I understand RMX does), reviewing RMC and outlining what options are being used. I copied the options that I use to a Word Doc (I own the pdf), and gave it to the PC’s as a handout. I also write up an outline for character creation.
Create detailed settings, cultures and have handouts, examples ready. The worst system in the world (which is not RM) can be overcome with setting. Have a strong idea of your theme, mood and a good ontological view of the world you create. I also create a vision statement that outlines the meaning of the story that I want to tell.
Understand the needs and wants of your players. Watch the PCs that they create and the motivations of their characters. Adjust your themes, moods and views according to the players. Listen as you have with your “Wizard.†If you have many d20 players, they may not care for RM, and that is ok. I don’t care for d20 or the New World of Darkness. This is mostly a matter of taste.
Lastly, I would still like to know the profession and what lists he knows?