In order to link the ARG1 of eat to the subject, you need to have eat
(and all other verbs) expose the INDEX of their SUBJ as their own
XARG.  The type that the auxiliary is inheriting from already
identifies its complement's XARG with its subject's INDEX.  Fixing
this will also automatically fix your agreement problem too, requiring
the auxiliary and the verb to have the same agreement (both agreeing
with the subject).  Pretty cool, huh?

Your TAM information isn't having any effect on generation,
because as yet, it's not getting propagated to the semantics.
The HEAD feature TAM is meant to be a pointer to the
TAM information on the verbal event indices, but that
linkage isn't specified in the matrix.
You can fix this by identifying HEAD.TAM with
HOOK.INDEX.E on verb-lex.
