The question I would ask myself here is how much I am willing to commit to changing my life for a person who is not even committed to herself.
We can't expect people to ever be anything more than who they show us they are (and not were - are, presently). What I have learned from being in a relationship with an alcoholic is not only that, but what we presently see is likely the best there is to come if that alcoholic does not commit to treatment.
That being said, as far as a few of your concrete questions:
It is not controlling to no longer drive her to places where she can get alcohol. She has the freedom to walk, call a friend, get on a bus, call a cab, purchase a bicycle as alternate transportation, or a number of things. If she has asked you to take her to a store so she can get items other than alcohol, and has ended up purchasing alcohol after you have made it clear that you would not be enabling her, then shame on her for breaking your trust. If that is what has happened, then she's made things harder for herself - you are not controlling by sticking to your own boundaries.
As far as the other two concrete questions you have asked:
What I have learned is there is no limit to how much an untreated alcoholic will push you and drain you. As far as coping skills - I would suggest reading the stickies on this board, at the top of this main section. Al anon would be a good group to look into, as it focuses on how you can properly take care of yourself and set healthy boundaries. As far as you drinking - I see that as potentially giving her a weapon to use against you. Drink at your own peril.
In my opinion, I am kind of in agreement that this job relocation is kind of a wake up call for you. You're being given a big decision to make, and there is absolutely nothing wrong with taking time to decide if you are going down the right path with your partner.
Whatever it is that you decide, just know that there are programs out there like al anon that can help you bring focus back to you so you can ensure that you are taking care of you, first and foremost, and placing healthy boundaries when you need to, so you can keep taking care of yourself.
And keep coming back here when you feel you need to. There is a lot of wisdom that can be gained from the members of this board.