We have given our 10-month DS both eggs and citrus already. I think he has had enough eggs to know that he is not allergic - we first tried them sometime between 8 and 9 months (I think). Our ped does not like giving babies egg whites under one year (although she is fine with yolks), but by the time she mentioned that, we had already given him whites without him reacting.
The citrus has so far been very limited, and I am not yet comfortable saying he is definitely not allergic. We gave him citrus around 9 months, and he broke out in head-to-toe hives the next day. HOWEVER, he was on an antibiotic at the time and our ped does not believe it was a food allergy, but rather an antibiotic allergy. Still, we have decided to hold off on giving any more citrus for the time being (probably until he is at least a year old).
Not sure about sushi! Would be curious to hear the answer to that.