It occurs to me that you could get away with most of that just by getting to perl, since perl can already call Python, Java etc. through the Inline:: modules.
And, for bonus points, somebody's already bolted perl into mzscheme -
If you do have a go, mail me at mst -> shadowcat.co.uk, I know a bit about the perl side of things and my first CPAN release was fixups to Guile.pm so I'd be interested to help you.
Hmm, Language::MzScheme isn't compiling against MzScheme v352. The documentation says it works with MzScheme v200 or greater, so I suspect it might not have made the transition to the v300 series.