By choosing your courses carefully in consultation with your academic advisor, it might be possible to prepare for doctoral studies. You should investigate closely the requirements of the doctoral program you are considering. In many instances the M.Div. degree might be a better choice.
The Integrative Research Seminar is the "capstone" course of the MA and should be taken close to the conclusion of your studies. It is an integrative seminar designed to help you reflect on your educational experience, including the academic, personal and ministry dimensions of your course work.
Certainly. The electives which are part of the M.A. are completely "free." You may take all of them in a single discipline area if you wish.
At present, the M.A. does not include concentrations. It is designed to let you tailor your studies to your interests.