I hate asking more questions, but...

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Well actually you can delete the breeding navlink from admin control panel. Also to answer your first question, this can be done easily be modifying adopt.php and doadopt.php slightly. There is a line that generates random gender in doadopt.php, delete it and add a dropdown gender selection script to adopt.php. This can be done with PHP forms, use $_Post in doadopt.php at the beginning of script to get the selected gender from adopt.php. This way you make gender selectable rather than random.