Hi Jake,
Do I need to repeat this process or just use one alias depending on which one my host supports?
You should only need one alias depending on your host. Does your host run common software, such as cPanel? If so, I can help you with the exact method to set these up on your host (in fact, cPanel is listed in the Help). If not, I advise you to ask your host whether this is possible and, if so, how to do it on their server. They may need to manually set them up, so just let them know you want an alias, for example, pointing bounce@example.com to |/your/site/cgi-bin/bounce.cgi
The CGI-setup process is very similar for bounce.cgi and signup-listX.cgi. You need one bounce.cgi file and (optional) a signup-listX.cgi file for each list (or set of lists) you want to subscribe users to. I recommend setting up bounce.cgi then doing signup scripts afterwards, if desired (form-subscription is the alternative and most used method)
Regards