Considering the Parable of the Good Samaritan [Luke 10], the openness of the Samaritan woman [John 4], and other passages in the gospels, can it be said that Samaritans were more God-fearing in heart than the Jews in general in Jesus' day? The Jews added a lot of extra laws; maybe the Samaritans were closer to the truth. Were they more like the Recabites of Jeremiah's age or the Amish in our day?

No, I do not think so. Actually the Samaritans had 5 books in their Torah but changed the 10 commandments a bit. They combined numbers one and two and their tenth commandment was "worship on Mount Gerizim"!  Their Pentateuch is a little different from the normal Hebrew version but not drastically different. I think you are right: they did not observe all the Jewish laws.

But I would not say the Samaritans were any more committed than the Jews. But they were less powerful. And they were the butt of Jewish jokes. (The animosity goes back to the eighth century BC (see 2 Kings 17), and especially to the 6th-5th centuries BC (see Nehemiah) when the Samaritans vigorously opposed the Jews trying to rebuild the walls of Jerusalem.) Since Jesus hates prejudice, he seems to have made a special effort to lift up the Samaritans.

Being in an oppressed minority does not make one inherently more righteous. It does, however, mean the Lord has a special concern for you. That is my view.