I was always under the impression that it was the Apostle Paul that was ultimately instrumental in turning Christianity from a largely fringe or heretical (depending on what side of the fence you're on) Judaic sect that had a following among Semitic peoples into one in which converting gentiles became instrumental?
Pretty much. Without Paul, Christianity remains a sect of Judaism that, with a lot of luck, could persuade Jewish high priests that newly-converted gentiles don't have to follow laws like circumcision (their children might still need it), and that the end-goal of Doing Good trumps Keeping the Sabbath. Paul really emphasized the Savior on the Cross aspect of Jesus, the one that emphasized how important it was that God Himself died for us. Peter and the others didn't, really.
That would be a logical course to start upon when converting people who had no idea of Jewish norms, customs nor wanted anything to do with them.
That's why Paul took it up as his personal cause.
This topic seems very similar in premise
to another without the predetermined goals. I think similar considerations need to be contemplated for both. I would also think a religion that advocates the principles of carrying the law and one which emphasizes on caring for a particular tribe within a specific geographic location according to scripture. It would be hard to advocate expanding borders or have some kind of ambition of conquest any larger then what is convenient that much unless one happens to already have a huge population base to create a desire for conquest. All this would mean something would mean an ATL starting before the Roman Empire. Also the fact that Judiasm is judged maternally also creates other social issues for such an endeavor.
Pretty much.
I'd like to state that, IMO, the only way to keep all the Abrahamic faiths united is to quash anything beyond Israelite Judaism. If your followers are restricted to a small area and population, heresies can be dealt with internally. Once your faith goes intercontinental, with millions of adherants, the logistics of reconciling two majorly different factions become difficult. Christianity is only 2,000 years old, and yet it has no fewer than four major theological sects (and that four is accomplished through lumping all the Protestants together into one block).