To patronize is to look down on some one. So for example u were at a salon and a hair dresser looks at you and says "oh let me fix your hair, i can make it look better" than you would say "don't...
Both are wrong She doesn't have or (she has) = present. She didn't have = past I don't have or (I have) we don't have or (we have) They don't have or (they have) He doesn't have or (he has)
"why don't you?" is a question. "why you don't" is a command. Why you don't? is not a correct question. Also it is not a command. Why can be used to give a suggestion or piece of advice eg. 'Why...