If there were children, I would have a life insurance for if they are young. If they are older, they would have to fend for themselves and I hope that they have the same attitude as Ãmy sister and myself have towards our parents:
We both hope there is nothing left when they die. If anything, there could be a lot of debt, so we can denounce the inheritance. That way we were sure that they lived their lives to the fullest.
And the muliple residences: I would rent short term. Think appart-hotel. That way you have hotel service without the worries of staffing and if you leave, it is not your problem anymore.
I would live e.g. 3 months in one city in a apprt-hotel and then leave for the next one if I want to or stay longer.
Sure, more expensive than buying a house, but if I have enough, why not?
Having a car in each place? Rent them. If you want a new one, rent a new one. If you look beyond Herz and Avis, prices can be very reasonable. Sure, don't rent a Rolls
The issue that you have is that you want to own things for whatever reason. I do not want to own anything. OK, the clothes that I wear, but that is about it. Some clothes that fit into a suitcase a wallet with some credit cards and I would be set.
No ownership, no long term rent, no binding with anything.