Here's an article about Roth IRA inheritance: Inherited Roth IRA
Spouse can treat as it as their own with all the associated rules about
when you can withdraw w/o tax and/or penalty. It's a bit scary to think about
what they might do.........do you know all the rules about when you can withdraw
after a Roth conversion (if that applies)? how would they know.
Do you have TIRAs? Would they know about RMDs? Hopefully the institutions
would remind them. Here, it's a bit scary to think about what they might not do.
Your goal is a noble one.....and potentially very useful. I commend you for thinking about it. Maybe one part , since it is likely that not everything will be thought of , would be where to get advice for the mystery stuff that is sure to surface. Maybe you'll inspire others, including me, to do the same.