Yeah, I broadly agree that all of these are valid things to consider, particularly if you are quite risk averse.

I take issue with (4) because if you have a mortgage you are already perfectly hedged against future housing costs. If you have a floating rate mortgage you are exposed to interest rates, but you can hedge against that by fixing your mortgage.

I think a blanket "debt is bad" approach is naive, just as much as a "risk is bad" approach is naive. All other things being equal, you would rather not have any risk or any debt. But for the right price, you should be willing to take on both. What 'the right price' is will depend on many things, like your stage of life, your income, your safety nets (the state, your family) etc. If you take a "debt is bad" approach then you are saying that the right price is infinity, which doesn't seem sensible.