I believe you know more about your own Italian experience than I do. At the same time, this is tricky because I have had scads of Italian friends and classmates who became upset when hearing Italian racial slurs. Maybe there's some attitudinal variation based on region? As for the term "Dago", I have a feeling a few Italians practice the same double-standard that bothers you about some black ppl: using the term on themselves but getting upset when "non-members" use that derogatory term.
I totally agree that racist speech is racist speech, regardless of the source. ... As for the prospect of racism disappearing one day, do you recall Dr. Suess's story about the "Star-bellied Sneetches"? (Or other parables, like "Animal Farm" by Aldous Huxley.) Nevertheless, the jury is still out, for me anyway, because I still want to be guardedly optimism.