Is there a way to change a core URL, e.g. /guidelines

Gotcha, yes, I thought I was clear on this. /guidelines and the actual admin-editable topic where the content lives are essentially identical. So, you are correct that I could make a permalink redirect to a topic if I really hated /guidelines for some reason. But neither redirect to a topic nor redirect to /guidelines actually would let the content live at a real /conduct location which is what I wanted.

Of the two options to redirect to /guidelines versus some full-length /t/ topic URL, I actually prefer /guidelines slightly.