May or may not work for your usecase, but I have some scripts to prepare read-only raspbian images here: https://github.com/nolanl/ropi https://github.com/nolan

May or may not work for your usecase, but I have some scripts to prepare read-only raspbian images here: https://github.com/nolanl/ropi https://github.com/nolanl/ropi There are commands to enable/disable read-write mode, so you can still make changes and do upgrades. I've had 0 problems with SDcard death after I started using it.