I can now confirm that it's working.

I compiled perl (with a bit of babysitting and ran make test with 2 errors. Also, expat, wget and gzip compiled and ran fine. Still used scratchbox to compile perl just because I didn't quite trust the onboard-gcc and now, have DBI, DBD::SQLite, etc installed via CPAN without any problems.

A There were some utilities that required installing like gnu coreutils that I didn't have when I started but they were easy enough to get on there.

Haven't tried any gtk apps but it'll probably just be a case of finding the headers before I do the compile.