There are no such things as stages. You either like ponies, or you don't.
*1 Covered. Likes ponies and is in denial.
*2 No, he's been posting for some time and this would be out of character.
*3 Given how frequently he complains about not liking anything in the show or understanding what we are talking about, I don't believe that really goes far enough to be a useful explanation. Close to covering the case of our Silver Dragon friend, though said dragon is basically a "Likes ponies but is in Denial" on account of not daring to watch the show because he knows he would enjoy it.
*4 No, Luka has been posting long enough for us to be sure this is not the case.
*5 Covered. Dislikes Ponies but seeks Attention.
*6 Seems interchangeable with *5
For what a Tulpa is, see Wikipedia and the last couple of pages of the thread.