Hey!
I can share some insight on your first question.
The first thing that you need to understand (any maybe you already do) that after 4 years of work ex and 2 years of MBA, you need to have a fairly decent idea of what kind of work you would like to do ideally for the better part of your working life. Of course, people make career changes and moves at later stages as well but the fact that your are mulling over these questions right now goes to show that you like to seriously plan things in life.
So,
the first question is around what truly is something you feel passionate about? After a certain stage in working life, I firmly believe that it shouldn't be about one dimensional attributes such as money and senior positions. It has to be more than that. This is especially true when you will realise just how much time will you be investing in jobs in Banking, Consulting or PE. At that moment, your driving force to continue working the 80-hour weeks or travelling 4 days in a week will not be fueled by the next bonus cheque or promotion. So, have an internal monologue to understand where your passion lies and research what keeps people in these jobs motivated. You can also consider taking up slightly different jobs, assignments, personal projects which test similar skills or involve a similar schedule to test if you thrive in these simulations, since you don't want to do any more internships. For example, you can maybe help a friend looking for to design a business plan or an entrepreneurship model or maybe try freelancing any business skills that you may have of your own (as a freelance consultant). These ideas are just on top of my head. I am sure you think of better
Second question you should ask yourself are about priorities in life. With jobs such as these, there are a lot of trade offs that you will be making. Understanding what lifestyle changes you will be expected to make (which also depends on what geography you choose to work in since there are clear cut differences in working culture of say US & Europe), what lifestyle changes does your health permit (I can safely tell you that the strenuous work in these jobs is not limited to mental exhaustion but also challenges physical health) and whether these changes are in line with how you see life in say next 10-15 years. This question can help you in two ways. 1) You will either be able to decide if this is the job for you or 2) you will be able to better prepare yourself (in advance) for life in the jobs
Third question is if there are any trends in these industries that you should be aware of before you get started on these. Coming from banking, I can safely tell you that banking as an industry is going through massive disruption in the hands of fintech. The industry is bleeding and hence a person really needs to evaluate how the next 10-20 years are going to look like. Since you are looking for transition, please research on long term trends in the industries which can help you make better choices.
I hope this helps!
Cheers