Well, I think many would consider taking in an 11-year old orphan and raising him as part of the household as an expression of kindness. At the time Vito made that decision Vito wouldn't know Tom was destined to be a lawyer. Also, Vito inviting very old friends from the neighborhood to Connie's wedding would be termed considerate by many.

For me , the interesting aspect of "the second his sweet nature and childlike qualities" passage is that it has very little to do with Fredo/Freddy as portrayed in the book. He's quite a cold character, actually.