How good of shape (physically) do you need to be in to be a nurse?

While nurses are on their feet a lot, I challenge that "all day" assertions. At the several hospitals I've been to, large and small, nurses generally sit to chart as well as to review patient records, pull labs, etc.

You probably spend more time on your feet doing the retail hustle than you will as a nurse.

That said, nurses do spend a lot of time on their feet and their generally moving throughout the day.

You scoliosis and back pain raise more of a red flag than your BMI. Many areas of nursing require lifting or assisting patients and that can tweak even strong backs with good body mechanics. Of course, there are areas with much less lifting.

You may find that some areas don't work for you as well as others do. Such limitations might present some challenges in getting hired out of school, though, because the experienced nurses tend to move out of the more physically demanding roles as they age.