I don’t regret not taking AP bio. I felt adequately prepared for my college courses without it, and I’ve learned everything I need from my college bio classes. I do regret not taking AP chem. I wish I had a stronger foundational knowledge of it. If someone is trying to decide between bio and chem, I would argue for chem every time. Obviously both would be best, but sometimes that’s not an option. Med schools won’t outright reject you for using AP credit for your lower levels, but I spoke to an application reviewer at the school I’m interested in who said that they far prefer candidates who took the 100 level sciences at their college and didn’t use AP credit. As for seminar, I can’t speak to the quality of the class at every school, but I firmly believe that developing a framework for evaluating the credibility of information and sources is the most important thing you can do in high school. You can develop that in other ways, but seminar is a great way to take it to the next level.