One wouldn't normally say 'Do you have it all'. 'It all' is generally know as 'everything' so you would say 'Do you have everything'
No, that would mean "You have everything?". So you use "have" before "you" to ask the question. Which means "have you everything?" or "do you have everything". "Have you everything" would also be a correct translation, since that is what you get when you translate it literally.