Thanks for this very detailed post!
I can confirm most of the points based on my experience also and the part about backup is essential!

I caught myself not doing backups or forgetting to set them up again after a clean install or switch to other distro way too often so I started packing all stuff to a script which I run after every clean install (one bash for linux distros and one powershell for windows ones).

The windows one contains removing some windows 10 apps not needed (like office hub, bingfinance and stuff that comes pre installed).

The linux one contains logic to create my working folder structure (dev paths, synchronizing some git repos, ...), set up backup to my NAS, installing a few packages like a nmap (things you need not often but when you need them, you need them fast) and synchronizing other settings.

So thanks for pointing out other important parts also like testing all DEs on a VM first, this is a real timesaver :)

Also I enjoyed reading the article because it was well structured and the personal experience in it made me feel like I knew every struggle!