1, No you would not say that unless it was backed up with a reason. You would say
I don't like him anymore or I stopped liking him because.....
2, No not correct also. The question sounds rhetorical and intraverted. you could say.
Do you know why i don't like him anymore? but I cannot think of a context on which you would use such a question.
3, This one is mostly accurate but in reality you would say:
Now he's going to be taking his driving test for the 7th time.
4, This one is good. I take it this is supposed to be in the past tense? if it was the present perfect it should be written. I didn't expect you to arrive so early.