I've just been rereading the thread to make sure I'm not forgetting what's come before. Man, I sure liked the intrigue you got up to in Luskan. Anyway, a few notes:
Just because Gromph didn't want to pay (or help) you to rescue Maccath doesn't mean she won't be welcome at the Hosttower.
In case anyone's forgotten, the original mission was to get the Draakhorn and get it back to Imani so it can be used to summon a Gold Dragon to fight Dretchroyaster (the Ancient Green Dracolich). Maccath knows how to use it safely.
Lastly, you let Imani know that she wasn't in Luskan and that you would have to go rescue her on Oyaviggaton. The only thing he's not telling you is what their original deal was, but it's not really important either.