I definitely share a lot of your sentiments about Jen's past history on the Avengers and her possible future on this team. I really like to give writers the chance to be creative. Jen and Thor dating is not reaching by a long stretch. In fact I like the idea. Having team members involved in a relationship can only help develop said characters. I'm not sure what Aaron is ultimately planning for her, but it could play out well to have someone in her corner as she's going through her trying time. It seems like Jen is in denial and having Thor there could bring back a quality dramatic feel that most team books have been lacking for many years. Since Jen doesn't have her own title as of now, I hope she will be a central point in this tale.
Here's to hoping Gail Simone gets a call.