I think you've done a good job of thinking about your options and their consequences! My question for you is: are you going to be able to enter the research program you want at this alternate university? If you are certain that you can do what you want, that is, you have a promise from a faculty member there that shares your interests, then I think you should pick one of your options that will result in your starting at this new program in Fall 2017. I don't think Option 4 is viable---most schools will not let you start a program if you are on a leave of absence from another (unless this situation is special). Also, it's unlikely people will welcome you back with open arms if you leave them, try something different and decide you want to come back.
So, if you are certain your Fall 2017 plans are going to make you happy, then take option 2 or 3. It really doesn't matter which one you take, do the one that you feel happier. I would pick Option 2, because it means more research experience and could result in a paper that will help you later. See also my note below on research interests.
However, if there's no guarantee that your current Fall 2017 plan will lead to the research position you want, then I think you should aim to start a new PhD program in Fall 2018, or "bite the bullet". Don't just jump ship to the other school because it's marginally better than your current situation---I think if you leave, you want to take the time to get in a place that is as close to ideal as possible. Thus, I would recommend staying the course with the current program and applying to new PhD programs this fall/winter for Fall 2018. I would not switch formally to a Masters program until after the summer. That is, give it until it's time to start writing applications to decide if you want to stay or not. If you complete a whole year at the program, your advisors will be more understanding that your research interests just don't fit the school. You would have done a lot of work for them and they will be happy to write you strong letters that can get you into the school that you want.
Regarding research interests: I agree with you that you should do what you want in life! But, I disagree that "life is too short to spend it doing what you don't want" applies here. I think it's true that you should not be spending your whole life doing what you don't want. But we are talking at most 1-2 semesters here, not the rest of your research career. As an academic, we all spend parts of our time doing research that are not our true passion. It's just the reality and nature of our line of work. I would encourage you to keep a more open mind. Your sentence,
strikes me as very immature, in contrast to your other well developed and thought-out reasonings in your post. I chose to say this honestly because I want to provide helpful advice and feedback. An academic/researcher should not be so arrogant that they would not consider working on things that don't line up with their interests. Again, this is not your dissertation work nor the rest of your degree. It's just something to work on until you get into another program. There are many other benefits to doing the work that aren't related to your interest in it.
