No, Snape is definitely not Harry's dad. James Potter is Harry's dad. There is no chance that there is ambiguity or mystery here. Snape was a rival for the affections of Harry's mom (Lily).
As Rowling explained in a series of tweets, Snape loved Harry's mother, Lily, and his unrequited affection drove him to resent Harry's father, James — and by extension, Harry himself.
Harry is clearly the Son of James and Lily Potter. He extraordinarily looks like James (as he finds out himself in PoA) and he has Lily's eyes- now these things are clear even from the first book.
Jay ends the series by promising to visit Gloria's family in Colombia sometime soon. Throughout the finale, Jay talks to himself aloud as he learns Spanish. Until that trip, though, he's promised to stay home and look after Joe while Gloria focuses on her career.
Based on characteristics, it is suggested that he has mental retardation. His mother delivered him to Mario because she did not love him for unknown reasons (according to Jeffy).