I took a lecture class that had sections, and the Professor of my class was the TA. I didn't really develop a great relationship with him (I went in to his office once, maybe a couple of email exchanges). The class had two papers, and he wrote great comments (Truly outstanding, top-flight work, etc.
First: Is it acceptable to ask a professor for a letter of recommendation in this instance -- i.e. where you received positive comments on your papers, but didn't really have a good relationship with the Professor? Have others here done this and gotten OK results?
Second: I want to apply to Top-14 schools; will it hurt me to have a letter of rec from a professor who has only taught me in what, from my transcript, is obviously a large lecture course? Will this set off some sort of red-flag?