Attention to detail is very important. I don't think you would automatically get disqualified for these little things... but if you reach someone who looks into details then it's not a good sign. There is nothing you can do now. Just relax (and focus on other applications, assuming HBS is not your only school).
However, when I review job applicants, I automatically pass to the next resume if I find so many careless errors on the resume/application.
Don't write anything. It will make matters worse. There are plenty of other schools with round 1 deadlines. You can also prepare for other round 2's.
Getting into Harvard requires tremendous amount of luck anyways. One can get rejected with even the "perfect application." Move on. Use your time and energy wisely.