Two thoughts about <mods:title>.
First, it seems there should be some standard way of dealing with initial
(non-filing) articles. I can think of several alternatives:
1.a. Make a content rule: "Omit initial articles."
1.b. Add a subelement <displayForm> as for <mods:name>, for the full
displaying form of title.
2.a. Make a content rule: "Include initial articles."
2.b. Add an attribute for the language of the title, so that applications
that care can strip initial articles when they have to.
3. Add a subelement for initial articles. E.g.
MODS test record example.
I mildly prefer 2 but it has the minor problem that the initial article
would not be available when converting from a 246 field.
Second, there are authority records for uniform titles, but there is no
"authority" attribute on <mods:title>. Although there is (to my knowledge)
only one authority for them, it seems to me you might still want to provide
authority="naf" to indicate the uniform title was under authority and not
made up. Also any other changes to MODS made for authority links for names
and subjects would be appropriate here.