Keep the relationship casual. Mormons observe the Sabbath closely, so Sundays are for attending church meetings and focusing on their spirituality. I wouldnt encourage my kids to date a mormon. After moving in with him it has become painfully obvious I have a lot of personal improvements to make to meet his minimum expectations as a wife and mother. You I think are ok with that. I know a guy who had a hobby of corrupting Mormon girls he was abused by his TBM parentsand I'm told you're both right. I do feel frustrated sometimes when spends his limited free time to go out with the guys, but I realize that he needs this release every once in a while.
Although with the change in times, people may not follow these rules as stringently as before, it is still better to be careful so as to not offend anyone, and you may possibly land up with the love of your life. It requires a special kind of patience, and I think that the phrase "absence makes the heart grow fonder" has to be something you can relate to. Typical American girls have the government to make them feel secure. The important part of finding a partner to marry does not, in my opinion, revolve around whether or not you are of the same religion.
I've been thinking more about your situation and another thing came to mind. You should take your cues from your partner, not from documentaries or this sub, on whether your partner's views and actions are manipulative, brainwashy and damaging. I know that she's even getting her stuff ready to go on her mission.
Because she already lives the covenants in most of the meaningful ways. If I even mention wanting to talk just about normal life things, I am told not to tilt the balance between problems and fun. We make time for each other every chance we get which sometimes is during the noon hour for lunch. Do you drink alcohol.