Ok, one question at a time. Since MacOS is Unix based (starting with OSX), I would think that the porting would be a lot easier than you would think (hopefully pretty painless). I am not going to say any definites as there may be someone here who has used Perl on the mac that may know of any caveats to watch out for.
Perl is open source so I am sure you can find the source. You can also check out the wonderful modules over at
CPAN.
Regards,
Jeff