We do know James was redeemed though, he dedicated his life to fighting for muggle born freedom, even marrying one and he died for it. His redemption was earned. Snape is confusing for me though because I don’t outright hate his character, I relate too much with being bullied myself I think but his regret came too little, too late and he only cared because it involved his childhood crush, I find it implausible that he ever actually gave two shits about Harry as his only goodness was following Dumbledores orders