James listed 4 of the 7.
Acts 15
28 For it seemed good to the Holy Ghost, and to us, to lay upon you no greater burden than these necessary things;
29 That ye abstain from meats offered to idols, and from blood, and from things strangled, and from fornication: from which if ye keep yourselves, ye shall do well. Fare ye well.
He gave the bare minimum. He knew that Gentiles wouldn't want to take on the whole Torah including circumcision. He also knew that gentiles were already under the Noahic Covenant. I posted earlier about Isaiah 56 and how gentiles were free to add to their observances of the covenant. As they learned more they could choose to observe more.
What's particularly interesting is that James didn't mention baptism, amongst other things as being 'necessary'.
As for the difference between abstaining from blood and from things strangled. I 'think' the abstain from things strangled is connected with 'kosher', how the animal is killed and butchered. But, that's just a guess on my part.
Therefore, even if Gentile believers were not bound, per se, to keep the ceremonial aspects of the Torah, it would be incumbant on them to keep the Feastdays in order to have loving fellowship with their Jewish brothers. Sadly, we did not do so.
I agree, it would have been nice if we had been taught to keep the festivals.
The best explanation I've heard for this is that these 4 things in particular were hallmarks of the pagan religions that the gentiles were coming out of. They were expected to immediatedly stop these practices and would learn the rest every sabbath day when they listened to the law of Moses being preached:
Act 15:19 Wherefore my sentence is, that we trouble not them, which from among the Gentiles are turned to God:
Act 15:20 But that we write unto them, that they abstain from pollutions of idols, and from fornication, and from things strangled, and from blood.
Act 15:21 For Moses of old time hath in every city them that preach him, being read in the synagogues every sabbath day.
BTW ET,I really enjoyed your post #310, lots of good information there.