My suggestions for the ESCL/CCL:
Basing the initial divisions off of this 70/15/15 formula is fine, but after that they should rotate every 2 years based on actual divisional records - worst team goes down, best team goes up. Sure, this year's Naz team may bump them up to a tougher division, but it would only impact 3 games a year for 2 years.
The schedule should be 3 division games, 3 crossovers mutually agreed upon to protect rivalries, limit travel, and balance schedule, and 3 true non-conference games.
I think that would be a nice balance of challenging division games, local/traditional games, and flexibility for programs to schedule as they need to (for example, St. Joe's has different scheduling priorities than Loyola). You don't stress AD's to schedule too many non-con games, you don't have any awkwardness like the DVC scheduling home and homes.
This - big conferences with several small divisions and promotion/relegation - could be a model for other leagues. It strikes a nice balance between having the majority of your schedule predetermined and having scheduling flexibility to allow for individual schools to schedule as they need to.