custtom settings for my SP site without using a list or having access to the farm/server?

Depends... Can you tell us what the custom page will do?

If you would like to add a new link to the Site Settings page you can add a Feature (using just XML) to define that link. That link would point to a page in a library like Pages or Site Pages. (examples: http://ift.tt/1OMm6iK , http://ift.tt/1EPtFxg

If you would like to add a new page to the _Layouts path, then you will need access to the server.

---

Mike Smith TechTrainingNotes.blogspot.com

Books: SharePoint 2007 2010 Customization for the Site Owner, SharePoint 2010 Security for the Site Owner