The hook you provided actually works almost perfectly, considering alicesoft games are always a pain in the rear to hook decently.
Just needs some extra steps.
First, select the right subcontext in the text hooker, 18F978 for agth or 18F974 for ith.
Second, disable phrase repetition option in the text hooker, it messes up with the next step.
Third, in Translation Aggregator go Tools->Manage Attached Contexts->Clipboard(in "Process contexts:" box) and set Phrase extension filter to Aggressive.
And done.
Like I said, works almost perfectly, but contains some system messages.
Many thanks for the h-code~