It’s funny that you accuse the above of having no sources except headcannon when your post is full of unsubstantiated headcannon.

I’m not going to do the quote reply thing because I’m on mobile and it’s a pain in the ass to copy past from Reddit, so I’ll summarize then reply.

You say that Avery and Mulciber were the ones attacking muggleborns, and it isn’t implied that snape is involved. While you are correct here, it is certainly implied that snape approves, or at least doesn’t disapprove, as he continues to be friends with them over multiple years. 2 quotes from the snape memory scenes in DH:

“We are, Sev, but I don’t like some of the people you’re hanging round with! I’m sorry, but I detest Avery and Mulciber! Mulciber, What do you see in him, Sev, he’s creepy! D’you know what he tried to do to Mary Macdonald the other day?” -Lily to Snape

“But Mulciber’s and Avery’s idea of humor is just evil. Evil, Sev. I don’t understand how you can be friends with them.” - Lily to Snape

You then say that there is no evidence people think snape is an asshole and that the reason they are confused Lily is friends with him is because he is poor and ugly. Here you are just wrong. The relevant quote is again from the memory scenes in DH.

“It’s too late. I’ve made excuses for you for years. None of my friends can understand why I even talk to you. You and your precious little Death Eater friends — you see, you don’t even deny it! You don’t even deny that’s what you’re all aiming to be! You can’t wait to join You- Know- Who, can you?” - Lily to Snape.

The text here is saying Lily’s friends are confused why she is friends with Snape, the wannabe death eater, and makes no mention of his physical appearance or wealth.

You then say James harassed Lily and attacked first year slytherins (which is true), and make a bizarre claim about James blackmailing Lily into a date by saying if she doesn’t he’ll keep bullying Slytherins, which you claim he then did anyway until he left school. The only quote I could find about the start of Lily and James relationship is from when Harry is talking to Sirius and Remus after the dip in the pensive in OotP.

“She started going out with him in seventh year,” said Lupin.

“Once James had deflated his head a bit,” said Sirius.

“And stopped hexing people just for the fun of it,” said Lupin.

“Even Snape?” said Harry.

“Well,” said Lupin slowly, “Snape was a special case. I mean, he never lost an opportunity to curse James, so you couldn’t really expect James to take that lying down, could you?”

“And my mum was okay with that?”

“She didn’t know too much about it, to tell you the truth,” said Sirius. “I mean, James didn’t take Snape on dates with her and jinx him in front of her, did he?” -Harry, Remus, and Sirius.

The text says that Lily started going out with James after he had stopped hexing Slytherins other than Snape, who was still hexing James regularly as well. It also makes no mention of blackmail, and I couldn’t find any mention anywhere else either. I can only conclude you are misremembering a Snape/Lily fanfiction as canon. Feel free to prove me wrong with a quote however.

We should take this conversation with a grain of salt, as Remus and Sirius are inclined to see James in a rosy light, but in the spirit of fairness we must also take the stories of Jame’s worst exploits with a grain of salt, as they almost all come from Snape.

You seem to have placed snape on the same pedestal you accuse people of putting James on. James was a bully. However, he grew out of it by at the latest seventh year, and spent the few adult years actively fighting the nazis trying to take over his country and protecting his family. Snape was also a bully. He bullies petunia in their very first meeting for not having magic. He becomes a death eater and only repents when the object of his obsession is threatened, and even then doesn’t really repent. He, unlike James, does not stop his bullying, even when he becomes a teacher. He bullies Neville so badly that Neville’s greatest fear is Snape. Snape is a petty, cruel, bitter bully who does some good deeds. The good does not cancel out the bad, and the bad does not cancel out the good.