You’re on the right track here, Bryan. If you’ll want your users to create pages with more than one segment in the URI, don’t use
{if segment_2!=""} {redirect="404"} {/if}in your template. I would just stick with it as it is in the first code sample of your latest post. I don’t foresee any issues with it, but if any edge cases arise, then I would simply deal with them directly when they come up. No need to overcomplicate things from the beginning.
Is there anything else I can do to help?