It's hard to give any advice on this until you detail the problem you're trying to solve. For example:
Where/why is your current system failing/inadequate/cumbersome?
Why do you want to move the data to s3?
Why are delete cascades important?
Where/why is your current system failing/inadequate/cumbersome?
Why do you want to move the data to s3?
Why are delete cascades important?