(1) The RCC teaches that Jesus gave the keys of the kingdom to Peter and that these keys were passed on to the succeeding Bishops of Rome. The Church therefore believes that only the RCC and those non-Latin Rite Churches in communion with the RCC are in perfect union together. Only by being in obedience to the Bishop of Rome can one be in union with the Church founded by Jesus for the salvation of mankind. As a non-Catholic, this is the best way I can answer your question. How did I do?
(2) The Church acknowledges that the EO have a valid Eucharist and Apostolic succession and have commonly been referred to as schismatics, at least until recently. They are now referred to as a "particular church". Please do not ask me to define said term, as I have never really seen it defined, but I would imagine that it basically means that they have valid sacraments and Apostolic succession, but are still not a visible member of the Church Christ founded. Pope Benedict recently praised the Orthodox, but stated that they are "wounded", because they are not in union with Peter. For a short time the EO and the RCC were kicking around the term "sister churches", but this has now been officially rejected by Rome in the last teaching document issued on the subject and seems to have been commonly rejected by the EO as well.
All Protestants are considered as "ecclesiastical communities" and not churches, as it is deemed that they do not have a valid Eucharist or Apostolic succession. However, since it is felt that most all Protestants have a valid baptism, they are now referred to as "separated Brethren" and are no longer commonly referred to as heretics, even though technically speaking they are heretics, though not in the same sense as the heretics who were originally Catholic at the time of the Protestant Revolt and then left the Church. Again, as one who has never been Catholic, how did I do in my answer?
I have said enough for now. It is time for someone else to talk, as I tend to talk too much.