dear Terry...
you quoted: "The High Priest was not a Pharisee, but a Sadducee, and the Sadducees were bitterly opposed to the Pharisees. How is it that Saul, allegedly an enthusiastic Pharisee ('a Pharisee of the Pharisees'), is acting hand in glove with the High Priest? The picture we are given in our New Testament sources of Saul, in the days before his conversion to Jesus, is contradictory and suspect." ...in galatians 1:14 paul states that he advanced in JUDAISM because he was exceeding zealous for the traditions of his fathers. the fact that he was zealous for the pharisee teaching and not the sadducee teachings doesn't mean that he couldn't or wouldn't join forces with the high priest to rout out the new christians. the saying is, "the enemy of my enemy is my friend"
paul had disagreements with the apostles about the need for the gentile christians to be "put under" the law as some of those laws seemed to be practiced in jerusalem but the JEWISH converts. it was these traditions that paul was against because he had spent his apostleship preaching grace or acceptance with God through JESUS (without conforming to the law)...his description of these other apostles as superfine was in regard to the fact that they had letters of recommendation and the congregation was impressed by that when, "He who glories, let him glory in the LORD."...and they had lost sight of the fact that it was paul who had taught them about their God and Lord and about the grace that is from Him...he thought of himself as their "father" in the faith. He was justifiably hurt AND concerned because these others could come in and sway the congregation to their way of "thinking" and the congregation could be so easily swayed...if they could be swayed in this way after all he had taught them, then what or who else might they be swayed by?...there is marked concern for the congregation .
you said: " his threat in 4:21, "Shall I come to you with a stick?""...actually he was asking the congregation if they wanted him to come in the same way as the superfine apostles...the "law" is considered the rod or "stick" by which a jewish person is judged see:ezekiel 20:37, isaiah 11:1-5 (being "under" the law, which the jewish apostles were trying to do to the gentile believers). paul continued in galatians 6:12-13 about how these ones were not preaching this for the good of the congregation. They were causing division in the "church"...whether they meant to or not, though it is unlikely because they did strive to be of the same Spirit. It is stated that paul continued to go to jerusalem and one would expect someone who taught about forgiving a brother would be the first to confront them and straighten things out. There is nothing to suggest that the church was irreparably divided over this issue as paul was ever willing to confront rather that cover up or gloss over.
love michelle