Updates to the MAC version can e.g. be found here. And as far as I have understood from other MacJazzers you have to stash the levels in your "Data"-folder. As said you should then be able to access them from the "Home Cooked Levels" episode.
If you'd like to try and let us know what exactly works. Mind though that you can only use v1.23 compatible levels! v1.24 (TSF) levels won't work for you.

And as said CTF doesn't work properly on local splitscreen games. (Thus being strangely compatible with the bug in the PC version....)