I am also terrible at punctuation and have a terrible time remembering which side to put the "$" when referring to money. As far as capitalizing pronouns, it is a bad habit that I have and something I unconsciously do. It has never been pointed out before and I'm not sure if I should thank "you" or not as your comment comes off a bit like an ad hominem attack. I am actively making an effort to be more positive so I will assume your intentions were good and instead say.
Thank you or Thank You? How about just Thanks for pointing it out!