Classes/Summer activities for admissions

<p>Hi guys,</p>

<p>High school junior here. I have a couple questions about admissions to Harvard, and how a few things will affect my application.</p>

<p>First, is computer science courses at Harvard. I took CS50/E-52 ("intensive introduction to computer science using C, PHP, JavaScript"), via the Harvard Extension School, and got a B+. I am currently taking another of Professor Malan's classes, Building Mobile Applications, this semester. I was wondering how these classes and grades might reflect on my application.</p>

<p>The second is teaching. I applied to be a either Teaching Fellow, Grader, or Course Assistant for the CS50 course for next fall (I had my interview last week), but I don't know how this will turn out. How beneficial is this to my college application? Is it worth it to perhaps sacrifice an EC or some courseload to pursue this (if I get any position, of course)?</p>

<p>Lastly, I am wondering what might be the best summer activity for me this coming summer. I am applying to several programs for high school students at colleges (Stanford, Rose-Hulman, and Harvard), but I also may have an opportunity to do a summer internship in-person with a game development company (S2 Games). I should note that I already have an unpaid (distance) internship with them. I may be able to make some combination of the two (college program and internship), but if I had to choose, which would help me form a better application to Harvard?</p>

<p>Thank you for any feedback.</p>