I think everyone has to work out what's best for them. I wanted a 'right and wrong' answer when I posted this, but now that I think more on it, there isn't one. I appreciate everyone's suggestions but money is a touchy subject and everyone views what 'should' be done differently.
I personally don't agree with only one account being shared by both people. I think each individual should have their own. I believe a separate account should be set up where both contribute for shared expenses but that can't be touched for anything outside of regular monthly bills or an agreed upon purchase.