There was a television show that my youngest sister watched called 'Sesame Street' and on that show, they would sing a little song that started out like this:
'One of these things is not like the others. One of these things just doesn't belong.....'
The differences of interpretation that developed between the Eastern and Western Churches are interesting, but I really think you have to take the Jewish concept of legal hierarchy and toss it out the window entirely to suppose that a high crime like murder would be mentioned in the same breath as the other three items in the Apostolic Decree.
What problem did that fix? What purpose would that have served?
To flesh that out a bit: A rift had developed early in the Christian movement and it became divided into a Jewish faction centered around James the Just and a Gentile faction centered around Paul. The Jewish faction were running around telling the Gentiles that they needed to be circumcised and follow the Law.
The Decree (mostly) mended that rift and allowed the two groups to fellowship together with a bare minimum of burden on the Gentile Christians. All the Gentiles had to do was conform to the requirements of the Ger Toshav (i.e. The alien resident.) Those requirements are even listed in the exact same order in which they appear in the Torah.
The entire episode leading up to the Decree and afterwards disolves into nonsense under the premise that, 'abstain from blood' is inclusive of a high crime like murder because both the Jewish and Gentile cultures alike already viewed as wrong.
So how exactly was it a "burden' for Gentile Christians to be requried to abstain from murder? How exactly was this a compromise with the Jewish faction? Was murder a problem for the Gentile Christians? Were they running around murdering?
James later equated the Decree with Paul's participation in the Nazarite ritual of the Second Temple Period (i.e. People of means defrayed the expenses of poor people who had taken the vow.) Paul was instructed to do this for the express purpose of placating Jewish believers who were zealous for the Law. That the Decree served that same purpose is clear and unambiguous in the context of Acts 21.