I need to know your opinion on Jack's and Juliet's weird relationship
Because for me it looks like most of the time Juliet doesn't really likes Jack that much- not even romantically but like, in general, doesn't like being around him very much (which, fair)
While Jack obviously is interested in her because of Kate's partial rejections and his time with the Others
But also on the flashsideways they are divorced and have more or less an amicable relationship and share a child, and given than the flash sideways is the happy eding every character wanted then it means is mutual and that Juliet did appreciate Jack on some level, but it just doesn't looks like it?
Hello Anon, thank you for the ask, this is a good one!
I need to make a little detour before answering it but I promise it'll make sense in the end.
So. The way I see it, LOST is the "unlikable characters who cry a lot" show. You see, all LOST characters are, from the start, morally grey but, perhpas, some are "greyer" than others. In this show the main characters are cheaters, con people, torturers, murderers etc. and you see them "crying" over their own "sins". There isn't much space for victims and justice in LOST and you're either okay with that or LOST isn't for you. Like, the whole premise of the show is that these people HATE themselves, they hate their past and they hate their lives. The character arcs end the moment they stop hating themselves, hence the importance of the flash sideways (and, imo, the writing cop-out that they are but that's for another day, not blaming the writers because they were in a tight spot but I'm not the number one fan of what they came up with, sorry).
Having said that, we can put up with the fact that we're watching the story of people committing horrible things because their story is tragic. As in, seriously, these people had it bad, like reaaaaal bad. And this is the second point of the show: bringing people to the extremes, forcing them to make a choice and therefore involving the audience in making a choice with the characters as well. It's not always pretty, in fact it's never pretty. We as audience are complicit in what our characters do and we can all together drape ourselves in the flag of tragedy and "justify" the characters' actions to feel less bad about them.
But, you see, among all these tragic characters Jack and Juliet's stories seem to pale in comparison. Like, their lives pre-island weren't exactly amazing but they were... ordinary. Loveless marriage, cheating, substance abuse, parent issues, sick relatives... I mean, this is "normal" life. So what I personally like to look at when I think about Jack and Juliet is that they're tragic because they're prisoners. Symbolically, they're prisoners of their own choices because they're incapable of moving on, "realistically" speaking they're literal prisoners of the Dharma initiative and, at large, of the island.
So, anon, you are right when you say that their relationship is weird because they're both prisoners and wardens of themselves and... of each other. There is no other impending tragedy over them: they seem to do okay in terms of finance, they're both extremely intelligent people with an impossibly high potential, they could do anything they want with their lives and yet they're stuck or, if we want to be corny, they're lost.
For Jack and Juliet the island is the embodiment of everything they've desperately tried to figuratively run away from and that they must face now. There is no escape, quite literally. This is why Jack "has to" go back: the island is his "purpose", something that, unfortunately, he could never find in the "real" world. This is also why Juliet "must" die on the island as well: on a symbolical level "death" means "accepting and letting go" (btw, I don't condone this specific usage of death in fiction, I have lots of things to say about it because I think it conveys a very twisted message wrt self-sacrifice/suicide but that's not for today).
So what's up with Jack and Juliet, then? Well, the thing is that they serve as a constant reminder to each other of who they are and of the things they should do to move on. It's not a coincidence that they "meet" in an aquarium/prison where Jack is written as a parallel to off-island Juliet: a "person" of science abducted and taken as prisoner on an island (they're on Hydra island by now) to help with something related to the specific field of medicine they're expert of.
This means that, the way I see it, it's not that Juliet doesn't like being around Jack because she doesn't like "Jack". As a matter of fact, I think she does like him as his own person but she doesn't like what she sees when she sees him because she sees herself in him. Also, another thing that I always say is that, to me, everybody on the island is a little bit in love with Jack but not everybody "likes" Jack. This is because getting to know the "real" Jack is a. very difficult and b. as much as I love him with all my heart, Jack isn't exactly the life of the party. Like, it's not easy to take to Jack, that's what I'm trying to say.
While Jack represents for Juliet a "bad omen" that says "you have to deal with your stuff or you'll always end up being a prisoner in situations you don't like", Juliet represents for Jack something akin to "hope". This is because Jack has an ambiguous relationship with the Others/the losties/ with the world in general, lol. He wants to desperately belong but... "he walks among us but he's not one of us". Unlike Juliet, Jack is actually "willing" to be a prisoner if this means that he could belong somewhere. This is why he's so tethered to the island in a way that Juliet both can and can't understand because she's on the opposite end of that spectrum (the difference being that she didn't "simply" crash to the island, she was unwillingly "complicit" in her imprisonment and she can't forgive herself for that).
Here comes the perfect metaphor in the flash-sideways: the divorce. Divorce is great, I love divorce. There should be more divorce stories. In the context of LOST, divorce, for Jack and Juliet, means that they can finally let go and move on, that they've failed and that's okay because failing doesn't mean punishment for life. It means that you can leave situations that aren't for you anymore and that's not the end of the world. As a matter of fact, it's actually best for you to do so. So yes, Juliet does appreciate Jack but she can't be with Jack despite the fact that she'll forever be bound to him (the island/the son they have in the sideways). And this is because, surprise surprise!, Juliet and Jack are the same character. In order for them to "grow" and complete their arcs, they must let themselves go, they must divorce "themselves". While on the island this is translated into literal death as I said above, in the flash sideways the writers opted for something a little bit more poetic: love. Love is also a form of letting go and embrace the unknown. Love is a form of meeting... the Other and... having faith in this encounter.
Kate and Sawyer are Jack and Juliet's respective Other, aka they're the ones who can help them move forward along their journey (and viceversa can be said for Kate and Sawyer, of course).
So, yes, anon, you got it right when you spotted the "push-and-pull" dynamic between them. I personally think they're attracted to each other but, as I tried to explain, they can't ever "like-like" each other because if they did, it'd mean that they like... themselves, which they don't (this is the characters hating themselve show as I also said above). The ultimate point of the show is for the characters to overcome this self-hatred and accept themselves for who they are. Hence, the divorce metaphor: Jack and Juliet will always be connected but, in order to move on, they have to let themselves go.