You can use the matlab bundle from the SVN repository. Octave is mostly compatible with the matlab syntax.
I didn't know there was such a bundle. Thanks for telling me. But where do I find it? I did find one from a few months ago (June) by kjosmoen, but this didn't seem to be on SVN - whereever that is located - and I don't know if it's the most recent.
Regarding your other questions, I don't know the answers unfortunately.