How to setup LLC as partnership but taxed as sole proprietorship?

I am creating an LLC to purchase a property and to make a long story short the bank requires that I have one particular person to be a 50/50 partner on the LLC with me. This person doesn't mind doing this, but basically just want's to act as an agent of the LLC with myself responsible for the building loan, having full ownership of the property and responsible for all profits or losses. Can I set this up in the operating agreement? In the future, with all parties permission, would it be possible to remove the partner and convert it back to a single person LLC? What would the tax implications be?