Thanks for the clarification. However when you say:

Suppose I am one of twins, but I don't know which twin I am. But I know that twin 1 will be hit in face in next 1 minute. In this case I am in the situation of so called indexical uncertainty and my best guess is that I have 50 per cent probability of being twin 1 and thus 50 per cent probability being hit in the future. After I will be hit, I will know with 100 per cent probability that I am twin 1.

This is really not unique to twins. Suppose I choose two strangers and tell them that I will flip a coin and punch one or the other of them in the face in one minute, depending on the outcome of the coin toss. Assuming the strangers stick around, they will be in the same position as the two twins in your example. So, I don't really see how this tells us anything interesting about identity, twins or copies.

Also, considering the first two of your three cases of copies, i.e. past copies and mirror copies, it seems to me that if I make a nondestructive copy of a person, the two will be mirror copies only for an instant; once the copy process completes and the two "wake up" (presuming that copying is done from an unconscious state), the two copies will immediately begin diverging based on different stimuli, etc., and will therefore become instances of case 1 (past copies). So, from a practical standpoint, there can be no instances of case 2 for any meaningful duration of time (that is to say, for enough time to interact with the copies).