Hi, Tim, and welcome - and thanks for a thought-provoking post.
I certainly wouldn't say you've lost the plot. Many of the reasons you put forward for wanting to become an expat are commonly cited here (as well as being dear to my own heart!).
One thing I would say, though, is that unless you really are comfortable living out of suitcases you're likely to find nomadic life either very spartan or worryingly expensive. (Both, if you're living in global cities.)
I wouldn't recommend making it a long-term thing if your resources are numbered in thousands rather than tens of thousands. If you can afford to, it'd be better to do more research, visit the best prospects in person, and then have an extended stay in the best one or two to see if you could settle there.
Bear in mind also that the costs of having to leave and re-enter your chosen country to comply with visa regs can mount up very quickly; and that if the regs change to your disadvantage, that could easily add to your costs.
So from that point of view, Mark's suggestion could well be worth pursuing.