We’re not offended; there’s a lot we do that they don’t (for instance, if you were really, really ambitious, you could write such a browser in our macro language ). You choose the tool that works for you.
As for German (or any other language) localization, that’ll have to wait for v10, as Multi-Edit’s design predates any conception of such localization, and it simply isn’t built to allow it. Sorry about that one. I was prepared to do a German localization when I came on board, as it’s the one foreign (to me) language I’ve studied, but as I said, that one is for the next version. But at least you know it’s planned for.
As for browsing files, essentially what you’re talking about is making the file-open dialog non-modal. No, it’s not written so as to allow that, but you can come close just by adding a command to the keymap to spawn the command shell (Windows Explorer, or perhaps Total Commander, or even a command prompt, to name three possibilities). If you’ve set the file associations in our Customize dialog (not from Windows Explorer), then any file you run via association from the shell will open in Multi-Edit, while the spawned shell remains open (if you ran it that way).
Not quite what you asked for, but it effectively does the same thing.