What about special abilities that the archer could do with the bow during melee? You've said that this class should be as martial as possible, and they're not proficient with shields. Maybe the archer could have a feat that improves his AC by using his bow as a 'shield' to try and deflect blows during melee combat.
The basic aim for this class is to create an "archer", which is old latin for "not-melee". And I'm afraid that I feel using a bow as a sheild...doesn't sound that possible (mind you, using TWD for a sheild bonus from a dagger, or arguabley, a fist is just as proposterous, if not more so). A dodge bonus, maybe. *sniff sniff* do I smell thread necromancy?
Oh, and for the record, I'm planning on using this class for an upcoming character (as soon as a new campaign in my area starts). I'll let you know how it goes!
For the last time, it stands for Shadow of Darkness!