Iv’e heard some people sing in HaMavdil, "zarenu v’shlomenu", while in most siddurim it’s written: "zarenu v’kaspenu". Where does the new version come from and is it legitimate?

Shalom Ari, Being that wer’e talking about a piyut (prayerful song) and not a halacha, both are legitimate. The more original version is a prayer for wealth (kaspenu), on the other hand, the Vilna Gaon (Ma’aseh Rav, 150), who is infinitely a greater authority than the unknown “Yitzchak haKatan” who wrote the poem, purposely changed it to a prayer for peace and perfection (shlomenu). His motive was apparently in line with our rabbis teaching that wealth isn’t important, and to the contrary, it often corrupts one’s values and priorities, and that it’s actually preferable to be middle-class. Rav Kook, as one who often follows the Gra (the Vilna Gaon), also follows this more idealistic and value-bearing custom in Olat Re’iya, saying "zarenu v’shlomenu", that’s what’s printed in Siddur Rinat Yisrael, and that’s how I myself do. With Love of Israel, Rav Ari Shvat