I'm super close with my family, and I'm not so sure how much I'd hurt. I prefer that the information be kept from me. Even with hearing the news, not a nit of my affection to them would dwindle. They've given me a good life and deserve appreciation for it. Them too try.
Concerning inheritance, I think an adopted child should not be shortchanged. According to the papers, he/she is a member of that family and is due to every benefit that every other child is.