Again, there were only two sides to this debate. ^You don't get to add your own arguments, 2000 years after the fact. This debate has been settled.
You are partially correct, there were only two sides but not the two sides you claim.
One side the Pharisee Christian from Jerusalem said that gentile Christian must be circumcised AND keep the law.
The other side Paul and his companions in Antioch, Syria dissented and disputed with them
Anybody can make the Bible say almost anything they want it to by quoting selective verses out-of-context. So let's look at your one verse in-context.
Acts of the apostles 15:1 And certain men which came down from Judaea taught the brethren, and said, Except ye be circumcised after the manner of Moses, ye cannot be saved.
Acts of the apostles 15:2 When therefore Paul and Barnabas had no small dissension and disputation with them,
Why would Paul dissent and dispute with the men from Judea about gentiles being circumcised if he was going to tell gentiles later that they had to study Torah in the synagogues? Would they not have to be circumcised to attend sysngogue?
Acts of the apostles 15:5 But there rose up certain of the sect of the Pharisees which believed, saying, That it was needful to circumcise them, and to command them to keep the law of Moses.
Acts of the apostles 15:10 Now therefore why tempt ye God, to put a yoke upon the neck of the disciples, which neither our fathers nor we were able to bear?
Is Paul going to say that circumcision and keeping the law was a yoke that even the Jews were not able to bear then later tell gentile Christians to go to synagogues, learn Torah and keep the law?
Acts of the apostles 15:19-21
19 Wherefore my sentence is, that we trouble not them, which from among the Gentiles are turned to God:
20 But that we write unto them, that they abstain from pollutions of idols, and from fornication, and from things strangled, and from blood.
21 For Moses of old time hath in every city them that preach him, being read in the synagogues every sabbath day.
This is the first of three times the four, and only four, requirements for gentiles are given. No command to attend synagogues.
Verse 21 is saying only gentiles have to be given special instructions because the Jews don't need it they already have Moses being preached in the synagogues every Sabbath.
Acts of the apostles 15:24
24 Forasmuch as we have heard, that certain which went out from us have troubled you with words, subverting your souls, saying, Ye must be circumcised, and keep the law: to whom we gave no such commandment:
Paul and the others gave no such command i.e. be circumcised and keep the law. Also no command for gentiles to go to synagogues.
Acts of the apostles 15:28-29
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.
The second time the four, and only four, requirements are given to the gentiles. And no greater burden than the four requirements. No command to go to synagogues.
Acts of the apostles 21:24-25
24 Them take, and purify thyself with them, and be at charges with them, that they may shave their heads: and all may know that those things, whereof they were informed concerning thee, are nothing; but that thou thyself also walkest orderly, and keepest the law.
25 As touching the Gentiles which believe, we have written and concluded that they observe no such thing, [keep the law vs. 25] save ONLY that they keep themselves from things offered to idols, and from blood, and from strangled, and from fornication.
The third time when the four, and only four, requirements are given to the gentiles. And again Paul says they gave no such command for gentiles to keep the law and thus no command to go to synagogues.