Very good points. A codebase that gets this VERY wrong is Gitlab. I think it might be a dumb characteristic of Ruby programs, but they generate identifiers all over the place. I once had to literally give up following some code because I could not find what it was calling anywhere. Insanity.
Another point: don't use - in names. Eventually you'll have to write them down in a programming language, at which point you have to change the name. CSS made this mistake. foo-bar in CSS maps to fooBar in Javascript. Rust also made this mistake with crate names. A crate called foo-bar magically becomes foo_bar in Rust code.
Yeah, translating between cases isn't exactly a problem IME. Might be neat to have a case-aware grep though, so you can get kebab-case, snake_case, camelCase and PascalCase all done in one go.