James 2:1 The key word here is "partiality," which in Greek is literally "face-taker" (prosopon and lambano). Jesus is said to show no partiality. The NET changes the structure of the sentence by adding an "if" clause, which is neither in nor even implied in the Greek.
2:4 The word for "discern/judge" here is diakrin-oo, which is used by Paul in 1 Cor, admonishing us to discern the body! Another time when divisions arose in the community. Fascinating parallel between two such allegedly divergent writers.
2:7 I think the Greek here points toward a Baptismal rite: "The name which was called upon upon (epi) you." The verb here, epikale-oo" does not mean belong, but called upon or invoked (literally in Latin).
2:12 The NRSV nails it on the head again here. The NIV and NET insert the word "give" as in the "Law gives freedom." This is not the case. The law of freedom is going to judge is what it literally says.
2:14 The phrase "Can such faith save you?" is probably better translated, "Faith can save him, really??" My theological question here though is -- who is the "him." The antecedent is unclear. James seems to be making the point about your neighbor in need, which is what most of the section is about. The truth is that your faith without works will not save your neighbor from his or her hunger. The question here, I think, is not about being righteous before God but rather doing righteousness toward your neighbor.