Is there a similar council, catechism or creed for the Orthodox Church?
No. Yes. No. The Church teaches that the bread and wine are "changed" or "altered" and become His Flesh and Blood without going into "how." It is a Mystery (Sacrament) and is beyond our comprehension. The Orthodox Church has not changed its teachings since the Seventh Ecumenical Council (when the Church was still visibly one).
The Orthodox Church sees the Eucharist as a symbol of praise and thanksgiving, not of continuous suffering and torture.
Do remember that the Last Supper was a Passover meal -- Passover is a commemorative observance, and that the Passover lamb is eaten but without its blood in the meat or separately.
OT laws prohibit Jews from eating flesh, or meat with blood or drinking blood, which is why the Apsotles reacted with unease at Jesus' words.
The Creed is the Nicene Creed (unaltered). It says that Christ suffered, died, and was buried and resurrected on the third day.
The Creed makes it cleared that the suffering part is in the past tense. Theologically Jesus is a man as well as God in the full sense of both. As a Man, Jesus died like all humans, once, not over and over. As God, He never died. God doesn' die or suffer.
I've always wondered why Roman Catholics say the Mass is a "bloodless" sacrifice
Can't help you there. You will have to ask an un-orthodox Catholic (?) for an answer. Why is it a sacrifice and how can drinking blood be bloodless? Hmmm.
I've got several difficulties concerning the Roman Mass, and I'm wondering if they applicable to the "Orthodox" church as well.
First why place Orthodox in quotation marks? It's orthodox, because it has kept Christianity as it was defined up to and including the Seventh Ecumenical Council. It has thereby safeguarded the Holy Tradition and the worship of the original Church as defined and taught by Church Fathers, using the Scriptuires in their original language and understanding. And, because it's the only one and unique and original and the oldest, it is spelled with "O," and because it is its official name.
Second, unless you specify what these "difficulties" are, how can I answer your question?
BTW, kosta50, why call the Orthodox, orthodox, if you are under the conviction that Christ taught something different?
I think you are confusing the "un-orthodox" with anti-orthodox or non-orthodox. I am Orthodox and could not imgaine not being Orthodox. I am inquisitive not in order to 'disprove' the Orthodox faith or to deny its orthodoxy, but in order for me personally to know it better.
Christ didn't teach anything different. We humans interpret what He said differently. The error is always on us. It would be too presumptious of us to assume otherwise.
The beauty of Orthodoxy is that it does not offer "rational" answers for things we cannot understand but only have a notion of -- like God for starters. Instead, it fully admits our mental depravity when it comes to God.
Orthodoxy does not have the vain streak of claiming to "know" God, or "understand" the mysteries of God's teachings.
Now, why don't you tell us more about yourself?