There have been multiple talks with the night elves throughout the lores history to settle on some sort of trade deal. The talks are almost always disrupted by another “bad guy”
they didn’t really go on any conquests until just recently, post-cata. beforehand they were simply securing the territories they lived in for their own survival
none of these things at all contradict with the value sets of protecting innocents as best as possible, being capable of forgiveness, and defending azeroth.