<p>I need to create some functionality in our SharePoint app that populates a list or lists with some simple hierarchical data.  Each parent record will represent a "submission" and each child record will be a "submission item."  There's a 1-to-n relationship between submissions and submission items.  Is this practical to do in SharePoint?  The only types of list relationships I've done so far are lookup columns, but this seems a bit different.  Also, once such a list relationship is established, then what's the best way to create views on this kind of data.  I'm almost convinced that it'd be easier just to write this stuff to an external database, but I'd like to give SharePoint a shot in order to take advantage of the automated search capabilities.</p>

Do it in a separate database, create a page(s) with controls that surfaces the data and run search over that. Loses quite a bit of the SharePoint features though.
Otherwise it may be okay to create a custom field control that will allow you to lookup the data in the other list. 
The custom field control can be the one to "view" the related data.
I know we have done it for parent child relationships between pages on the same list. Not 1-to-N though.
Tough choice either way.