The beginning was very amusing, but it did feel as if it moved a bit too fast. You did a wonderful job portraying their close friendship from the start, but the way they jumped into bed together so quickly almost seemed to diminish that.
Interesting idea with Locke being against the Empire before Rachel. I'd always assumed that she'd been his primary motivator for rebellion and joining the Returners, but by establishing their friendship so early, it gives an extra motivation.