I am having a change of heart during the protection of Kimball quest. If I were to snipe Aaron and leave would the Leigion take me in or would I have to visit yes man? I believe I am vilified with the CL. What are my options?

I don't think that killing Kimball would get you accepted by the Legion, but hated by the NCR.

Pretty sure you've already failed the "don't make the Legion mad" quest at that point; it's Yes Man or NCR for you.

Yup its too late Same thought came to my mind when I was helping Mr.house but It was too late and i wasnt even at the dam part yet.