This part only partially addressed.
When they heard this, they praised God. Then they said to Paul:
“You see, brother, how many thousands of Jews have believed, and
all of them are zealous for the law.
All the Law!
Hebrews 6:4-6 says that some were crucifying Jesus afresh and putting him on public display as a mockery.
Paul was simply following a Nazarite vow you say? It had to have animal sacrifices to do that.
And, the Nazarite vow involved animal sacrifices! While all were taken care of on the Cross once and for all!
At the end of their vow, the Nazirite brings three sacrificial offerings to the Temple in Jerusalem.
The first is a ewe for a chatat (sin offering), the second is a lamb for an olah (elevation offering),
and finally a ram as a shelamim (peace offering) along with a basket of matzah and grain and drink
offerings."