After some adjustments to the various render settings, I remembered the render time setting (in seconds) and set it at two hours, fixing the time issues I was experiencing. Sometimes wrapping my head around the differences between 3Delight and iray takes a few tries before I realize the tutorials I've read gave me the answers, but they've just sunk in too well!
So now I've got nearly two pages of renders complete with more scenes set or needing to be. Everything looks great so far; I'm happy with the texture rendering and ease of creation of lighting rigs out of simple objects for fantastic new effects.
There's a lot of work ahead—and I'm glad I upgraded to finally bring my imagination through to the final renders.