In an apocalyptic winter filled with zombies, Juliet is on a rampage to kill Romeo at all costs.

The last draft of the logline reads better and adds clarity over the original one. Most loglines don't include character names so don't feel bad about omitting them. The only reason to include a character name is if the name informs nature of the character in a story critical way such as Jesus or Gandhi?

In this instance as previously mentioned the names are not fulfilling that role.

I would drop the left for dead betrayed by her true love is enough for an inciting incident. I would also change the character description to reflect more about the Mc nature and flaw than "...one woman?".

After she is betrayed by her true love during a zombie apocalypse a shy librarian must take up arms to exact revenge against her fianc?.

I would add perhaps that she must lead a group of patrons to freedom in to the mix or other wise give her an additional hurdle to over come.

Alright. I'm clearly outnumbered. While I do put those themes in the script, the themes would not be shown in a Wikipedia synopsis, or at leastvery little would so to speak. Looking through it again I see it more than I feel an audience would. So instead I should write; "After being betrayed by her true love and left for dead in a jail cel in an apocalyptic winter filled with zombies, one woman goes on a war path to exact revenge against the man that betrayed her."
Feels goofy without names but this probably send the message clearer

If you use their names, there is no way readers are not going to associate your story with Shakespeare's play. As I certainly did . This raises certain expectations as to what your story is about. And then when you say the semblance to Shakespeare's play is only 'superficial' -- well, now I'm really confused. Now your logline creates the impression of a bait and switch. Which, of course, is not your intention. So, yeah, it's probably better to drop the names.

Finally, what makes Shakespeare's play a classic is that it is about a universal theme -- love, specifically about love arising in the context of hate. The theme and resulting conflict has universal appeal -- it's something people can identify and empathize with across all cultures and all time. More important than whether your story has any semblance to the play is whether, like Shakespeare, you are writing about a universal theme, a universal human predicament.

The story is that Romeo and Juliet were once together and madly. The thing that separates them is what also created the zombies, an experiment led by Romeo. It's also in this that he betrays Juliet by killing her brother. He ends up putting her in jail and basically leaving her for dead. Not only does she want revenge for the betrayal but because she was bitten in escaping, she has little time left. I wanted to use the passion that they exert for each other and flip it, reversing the quote 'my only love sprung from my only hate' so to speak.
That said I actually thought of changing their names cause there isn't much superficial likeness to the Shakespeare play but at the same time it felt like I was taking away an intrinsic part of the idea/story. You make a point, the story, while having deep roots in the Romeo and Juliet story in its sorta flipped way, is nothing like the actual story at the very least on a superficial level, therefore maybe drawing more confusion then anything else. So I guess my question is, should I leave the names in, is it worth it to take out their names in the logline and still keep it in the script or change it altogether?

From what you've written here so far I don't see the justification for mentioning the names Romeo and Juliet. Reason is, that combo of names resonates with such particular story lines and characters that unless you do a Bazz Luhrmann style modern re telling and stay true to original dialogue and character dynamic you are miss leading the reader and audience.

The only other way I can see this done credibly is ala Pride and Prejudice and Zombies parody the original with a cross over genre.

Note that in Oh Brother Where Art Thou the only element retained from the Odyssey is the most of the structure and mentors as it was loosely based on not a modern re telling they didn't call it The Odyssey.

What is it that happens to these lovers in this Zombie story that is different to others and makes it unique? What is the primary inciting incident for the MC that makes her need to achieve her goal?

Unlike Pride and Predjudice and Zombies, which is the exactly Jane Austen story with zombies shoe horned in (as well as being aimed as mire of a comedy as far as I know), this script is more like Oh Brother Where Art Thou, a more 'modern' retelling with a twist of its own. Not an accurate comparison but the most similar.

Nathan Philips, thank you for clearing that up. I may tweek that first part of 'left for dead' to something that is more descriptive in the script but apart from that, the rewrite is good.

The concept will inevitably have to compete against the other zombie parody of a classic, "Pride and Prejudice and Zombies", the book and now a movie in post-production. In what way will the zombie treatment of Shakespeare's famous play distinguish itself from the zombie treatment of Jane Austen's famous novel?

I think the reason you should add the stakes is because the logline is not what you should be using to hook the audience. To quote the guidelines from this page, the point of a logline is to "demonstrate that our story contains the essential components." Without a stake, a studio is less likely to see it as a complete story, and less likely to be interested. The execs won't necessarily want to ask why Juliet wants to kill Romeo- they don't have the time to read the full story just to find out. They just want to know there is a credible reason that can sell, to convince them that looking at the rest of the story is worth it. Also, having he stakes included doesn't give away the story, but adds that essential element, potentially making it more interesting to the audience at little cost. See what you think of the one below (with a generic/random stake added), and see if you think it kills off the line or adds value:

"After being left for dead in an apocalyptic winter filled with zombies, Juliet is on revenge fuelled rampage to kill Romeo at all costs"

I guess my hook is for the people hearing the logline to ask why. To hint that there is a reason that the famous star crossed female lover suddenly wants revenge but not say it would allow the listener to imagine and only find out what it is by watching the film. I kinda want to play on the premise that everyone is so familiar with the story and have it flipped there fore have people guess without giving it away. If I add more, I believe it would give it away. So knowing this should I still say why she wants revenge?

I'm sorry for being bullheaded. I do think you make a valid point as to adding the stakes.