I had a very similar Giant Revive DX conversion a while back, with a front 9C on it, and kept the rear end cassette and pedalling capability. You would loose your front disk brake probably if you did that. I replaced the stem with monkey bars. The twitchiness was substantially reduced with the motor mass on the front, and a rear battery that seems better balanced against the massy front motor than your configuration. It was a very nice comfortable ride, not the greatest for pedalling given the geometry, but very fun and unique ride.Widening the handlebar helps to reduce the twitch offering finer control of turning on the contact patch. The rear rack was a decent spot for the battery, with the hub motor on the front. So I think your bike is tail heavy, a bit twitchy, and no pedalling offered. This could be improved.