Couple of issues:

First:
What does "When the page has been rendered" actually mean? Does it mean when the form is first rendered to the user?

Second:
When you add a workflow (just send an email) at "When the form has been Opened", instead of rendering the form, it displays "Previous" and "Next" (the form i set up was a single form, no steps added) when I lload the page up.

When I click on "Next", I get the confirmation screen rather than the form. I have to press the "Previous"button to get the form.

So, i thought it might need a step process rather than a single form for it to work correctly - but when i do this and I load the page I am still presented with "Previous" and "Next". This time however, "Next" takes me to the second step and "Previous" takes me to the first step of the form.

Also during this whole process (including after submitting), I never recieve the email that was meant to be actioned "When the form has been Opened".