Were you able to figure this out? I am going to move this topic into Community from Support because you are raising interesting questions about how to onboard your new members, and you have an approach (you describe in this post above) other members here might be interested in learning about and potentially helping you with.
It occurs to me you could also address the concern about making sure new members see a certain topic by bannering it. Bannered topics are shown to everyone and then they can manually dismiss it when they are done with it and no longer want to see it.
There likely are ways to automatically move people through the “Newbie peppers” and “Seasoned peppers” groups, using the trust level system and badges. Or you could just rename the existing trust levels and adjust the requirements for those. Other members here might have some suggestions!