This is a response to you and to anyone considering Columbia MPH: The administration at Columbia definitely over hypes the difficulty of the first semester and suggests that students should not work, but it's totally possible to work part-time if you want - I did it and so did many of my classmates. There are a lot of courses, but only about half of them require actual brain power. I think that if you do decide to attend Columbia for a MPH, know that you will encounter students and faculty who are extreme in their political beliefs and will make sure you know it lol. Some faculty members have made strange comments that prompted formal complaints from students, such as our Science, Evidence, and Public Policy professor claiming that pro-life people are the same as people in the Taliban. Although there are people like him, there are also a lot of faculty members who make themselves very available to their students and are genuinely interested in your success, personally and professionally. If you are open-minded and can associate with people who may think very differently than yourself, then Columbia is a great option. If you prefer to not be confronted with possibly emotionally charged debate every now and then, consider another school.
Additionally, I believe NYC offers unparalleled opportunities and being able to call yourself a Columbia MPH student really puts you ahead of other practicum/job applicants in the area.
As for application tips: keep in mind that the majority of Columbia MPH students have impressive professional backgrounds. Make your experience and character the theme of your application.
I hope this helps!
