Hi Holger,
I personally have shellcheck plugin in my editor (atom) which performs checks in real time when I write shell scripts, I really recommend using it if your editor supports it.
Regarding checking stuff with shellcheck, it can be fine but it may be dangerous requiring fix of all warnings/errors, since some of them are sometimes really hard to fix. For instance doing some stuff in posix shell bs doing it for bash or whatever.
A related topic could be discussing about using "uncrustify" to force correct code format to be applied to code during gerrit jenkins job.
Regards, Pau