werent connie or michael uncoftable with the fact that Sonny and Lucy had had an affiar and that the new heir to the corleone family was in away a "hoax" because he never came from Sonnys wife and shouldnt really be in the direct family? Also did Sandra know and how was she about it all?

Didn't have to come from Sonny's wife. He was Sonny's blood, Corleone blod. Who the wife was is insignificant as far as Corleone blood is concerned. As for Sonny's wife knowing, watch the movie, it is obvious at the weeding that she is aware that Sonny is going with Lucy. Remember something, and not that I agree with the thinking of that era, but this took place in the 1940's and at that time woman had absolutely no say when it came to those things. Especially in a mob marriage!


Don Cardi

In one of Michael's (rare) "godfatherly" acts, he made sure that Lucy wasn't just dumped after Sonny died. In the novel, he getgs here a decent job in the Vegas hotel where Fredo was sent following the Don's shooting. And she was Connie's maid of honor, so they were pals for life.
On the other hand, Sandra, Sonny's widow, just about disappears after Sonny's death. We see her briefly in a deleted scene in GFII when, in another of Michael's (rare) "godfatherly" acts, he blesses the marriage of her daughter Francesca to a Nevada WASP.