What if Lily hadn't died, would Snape still be a Death Eater ?

No, Snape would have remained বন্ধু with Lilly and would have loved her from a far. Because of their friendship, he would not have become a Death Eater.

Snape had already become a death eater in the life of Lilly but, yes, his life may be not like a typical death eater since he possessed the capability of true love. However, his life had taken a turn out of remorse on Lilly's death therefore if Lilly Potter had survived and had continued her life with her family, Snape had remained a death eater অথবা had gone to some hidden place just to live a lonely life with a broken হৃদয় and হারিয়ে গেছে dreams. In case of prophecy revealed and Lilly still survived Snape had definitely had switched the sides for the sake of Lilly.

Probably. Snape's motive to going to Dumbledore was because he was trying to protect Lily. It might not have been absolutely necessary for her to be killed; Snape might have fought against Voldemort just to keep her protected, and prevent her from dying.

However unless Lily was endangered, his emotions and প্রণয় of her most likely wouldn't have been brought up, and he would have stayed a death eater.

It doesn't really matter was Snape's reason to যোগদান Dumbledore was, though, if you're going to use the উত্তর to this in an anti-Snape argument, অথবা something. He joined because he was able to love, and the fact that he only loved one person, instead of the whole wizarding world, say, like Harry does, doesn't make a difference. Really it doesn't matter if আপনি help save the world because of altruism অথবা a need to keep Lily's son alive, to make her happy in death.

But, no, if Lily hadn't died, অথবা at least been endangered, Snape would still be a death eater.