While I agree that if Lucy hadn't expressed an opinion Becca or Elaine would probably have strung her up, Lucy has expressed an opinion. I'm pretty sure the fact that Lucy doesn't care about her anymore and thinks her punishment was enough would be enough to get them to stay their hands.But the love route makes no sense because if Becca, Fiona or Elaine knew what all that bitch did they would never find the body.
The reason I didn't mention Fiona there is becuase Fiona does know what Tanja did, and she does know the relationship between the MC and Tanja. Again, I think they all respect Lucy and your wishes enough to just let it be.
Although K7 has said that Tanja and Lucy will never meet again, I do think it'd be a good scene to finally have them meet up, not intentionally though. Just have the MC and Lucy on a date in town and just bump into Tanja accidentally. Lucy is kind of annoyed at first, cos she thinks that Tanja is gonna apologize to her and she (as has been stated) doesn't want to hear it. But Tanja doesn't apologize; she thanks Lucy for her part in killing the evil sociopathic bitch she used to be, and wishes her well before leaving Lucy and the MC to their date.
Could get followed up a couple days later with a talk on the beach about how Lucy felt about the whole thing. Anyway, I think it'd be interesting at least. But I'm not super attached to the idea or anything (not trying to tell K7 how to make his game after all).