Yes, that's all you could do. Sounds like just a slight memory fault exaggerating it, something I'm sure we're all guilty of. Booting "exclusively to amigaDOS, without the ...windowing system available" was not possible, as the CLI ran in a window.
This is correct. I just can't quite remember the exact details nowadays. But now you say it, I think that is what I had, just a single cli window :)
You could use alternative shells, though, and they weren't quite as painful. Bill Hawes's 'wsh' was rather nice.