Well, not sure what exactly was causing both the form and tree views to show up as type "tree" in the debug window, but I figured out the weird title issue. Turns out that Odoo really wants to have a field called "name" in your model, and that's what it displays at the top of a form view, at the end of the breadcrumb trail.  The "string" attribute of the "form" tag (I wish this editor had a [code] button) is ignored.  Odoo will use the "string" attribute of the "tree" tag as the title of the tree view.  Since my model only contained fields "alpha_code", "description", and "num_code", I was getting the funky title at the top of the form view.  I didn't see anything about this in the several pieces of scattered documentation that I could find.  Hope this info helps someone else.