Hi Jim,
you could use Last Pass for auto login on the website. You could set the web browser's start up page to the catalog item link, like https://live.hornbill.com/instance/catalog/new-service-request/com.hornbill.servicemanager/15/59/ and when Last Pass signs in automatically, it will redirect you to the catalog item page.
I'm unsure if there is a way to have a public facing catalog item, but you could set up email messages to create automatic requests.
Thanks