This is great! Your last point makes a lot of sense. I wish I had taken advantage of that as a premed. Simply saying thanks for the teacher’s hard work that semester makes so much sense. Many premeds don’t realize that getting a “good” letter of rec is not as easy as one would imagine. The solid professors will be asked by half the class. Forming a good rapport early on will set you apart and they will actually want to write a letter for you.