1) Yes, it’s an appropriate name.
2) 丹 means “red” as an adjective. It can be associated with “heart” to mean “loyal heart” (丹心) and with “green” to mean “history” or “painting” (丹青).
義 means “righteousness / chivalry”. It is often associated with “air” to mean “loyalty” or “sense of obligation” (義氣).
3) There’s no negative meaning in 丹義.
2) 丹 means “red” as an adjective. It can be associated with “heart” to mean “loyal heart” (丹心) and with “green” to mean “history” or “painting” (丹青).
義 means “righteousness / chivalry”. It is often associated with “air” to mean “loyalty” or “sense of obligation” (義氣).
3) There’s no negative meaning in 丹義.