Were Peter & the eleven taught to keep the law by Jesus ?
Jesus and his disciples lived as Jews, pre-cross. MAD's issue is post-cross. Even Christians keep the moral (not ceremonial, civil) laws of God because we love Him, not in order to be saved (unless you are extreme antinominian and think adultery, murder, idolatry, lying, etc. is fine as a hyper-grace heretic).
Peter & the eleven were to evangelize all of Israel, did they do this?
The 12 did begin the Great Commission, but did not complete it. It is still going on today and Paul's followers also have not evangelized all either. The early church did start out with Jewish Christians based on the one gospel of the risen Christ (death, resurrection). Paul shared the same gospel and expanded the gospel to the Gentiles over time (without personally reaching all). There was a shift from a Jewish center in Jerusalem to an Antiochan Gentile center over time in missionary strategy, but the same one gospel because there is only one gospel, one Christ, Jew/Gentile one in Christ post-cross, pre and post-Paul.
Was all of Israel converted ? What is the point? Israel did go on to reject her Messiah as a whole despite individual Jews converting.
Do we become Jews now ?
The early church did not become Jews to be Christians. Just because some retained Jewish background does not mean all did or that it was a gospel issue. There was transition from old to new and Peter had to get up to speed on the details. Peter and Paul both preached the risen Christ, the only way to be saved by grace through faith apart from works.
Was Israel cut off ?
Rom. 9-11 shows that there was a shift from Israel to Church. You confuse individual salvation of Jew and Gentile through the one gospel and future, national, covenantal, eschatological issues with Israel (MAD proof texts reflect this confusion).
Is Paul the apostle to the gentiles ?
Paul is the apostle to the Gentiles. So? Peter and James initially, primarily, but not exclusively focused on Jews. Paul reached Jews first, then went to Gentiles primarily, but not exclusively. They all preached Christ and the ONE gospel, the power of God.
Two target audiences is NOT proof of two different gospel messages (Gal. 2:7 demarcation of ministry, not divergent messages).