Hello Jason, have you been away for a while?
You've been playing this game as long as me so you know all about when and where to assign your HQ generated DP and how best to incorporate this into your research strategy. I doubt very much if you'll be relegated but you're unlikely to be competing for the championship this season.
The rules for changing league were revamped just over a year ago, below is a link to Jack's announcement. Very little has changed in terms of dp allocation. The ideal time to join a league is during the inter-season break because you receive maximum design assuming your current active CD has been designing the car for the past 17 races.
New Design Balancing system when changing leagues
I hope this helps and welcome back.