I understand your confusion! To be honest, your message is extremely difficult to answer, there is plenty of evidence that they are not lovers, as you point out in your message: they “absolutely hate and insult each other” during IWTV (and in later books, too), and yes, Claudia tries to kill Lestat 😛 Those aren’t signs of love.

In my reading of canon, they do get together, but it is always a fragile “together.” They meet before Lestat’s concert, they are together at the end of QOTD, etc., there are many times in canon when they are physically together but, it is usually thick with the tension of whether it can last ;A; Perhaps that’s another reason why the L/L shippers make so many fanworks; we just don’t get enough L/L explicitly in canon.

When Anne Rice wrote IWTV, Lestat was clearly the main antagonist (other antagonists included Santiago, the theatre vampires, etc.). Lestat was intended to antagonize Louis. At the end of IWTV, one can say that Louis has won; even if he might not be all rainbows-and-sparkles-happy about life, Louis ends the book at least as a functionally independent vampire, whereas Lestat is miserable and broken, seemingly having difficulty even hunting for mortal victims on his own (dependent on a young “nurse vampire” bringing him a victim). There is disagreement between Lestat and Louis whether that scene even happened, but, whether it did or not, by the end of IWTV-era, it seems like Louis has overcome his abuser/monster and is the stronger one of the two of them.

Still, L/L did explicitly share some intimate moments in IWTV, when Lestat fed on Louis, and sharing the intimacy of the Dark Gift (the most intimate experience for vampires), and beyond than that, Lestat tells the reader in TVL to “Read between the lines.” A relationship does not need to be explicitly stated to exist, it is up to each individual reader to decide whether they want to ship those characters or not based on their reading of the story.

Personally, I ship

Louis/Lestat and thankfully, I have found plenty of other Louis/Lestat shippers in the fandom! Anyone is welcome to reblog/comment on this post as to why they ship Louis/Lestat ❤

TL:DR; Throughout canon Lestat pines for Louis QUITE A LOT. It is my personal belief that most of this pining is to “make up for” all the awful times during the years in IWTV when Lestat abused his fledglings, when they fought back, when Lestat was frustrated at being unable to give them the truth of their vampire nature by sharing his knowledge with them. To make up for the scenes that were not explicitly described in IWTV.

1) Here’s Lestat talking about Louis, from TVL:

I fell fatally in love with Louis, a young dark-haired bourgeois planter…  Louis gained a hold over me far more powerful than Nicolas had ever had…

And why should I bother to tell of the times he came to me in wretched anxiety, begging me never to leave him, of the times we walked together and talked together, acted Shakespeare together for Claudia’s amusement, or went arm in arm to hunt the riverfront taverns or to waltz with the dark-skinned beauties of the celebrated quadroon balls?

^You could say he lied about any of this, we do have unreliable narrators. That’s up to you as a reader to decide if you believe Lestat’s account on this or not.

2) More of Lestat talking about Louis in TVL:

I kept glancing at him and away from him, as if his green eyes were hurting me. In modern parlance he was a laser beam. Deadly and delicate he seemed. His victims had always loved him.

And I had always loved him, hadn’t I, no matter what happened, and how strong could love grow if you had eternity to nourish it, and it took only these few moments in time to renew its momentum, its heat?

^This seems, again, to be very clearly stating that Lestat loves Louis. Whether that love is reciprocated is up to the reader’s interpretation.

3) In the immortal words of @high-fructose-lesbianism: “Now matter how hard you ship Louis and Lestat you will never ship Louis and Lestat as hard as Lestat does.” [X] Part of why it’s such a tough ship is that AR just does not let us have much in terms of explicit canon fluff of them! It mostly happens off-screen. Which is where fanworks steps in to satisfy that need ;] I have some more of this kind of thing mixed into my #nobody ships Louis and Lestat harder than Lestat ships Louis and Lestat tag.

4) Also relevant: Anne Rice was answering Fan Questions for Lestat at one point and she said (in character as Lestat):

“…but if I did have to choose, [my one companion for all eternity] would be Louis. My longest most enduring friendship and love affair in this world was with Louis. And though his limitations can be maddening, they can also be as inspiring to me as his virtues… the best choices we make are not always the wise choices. Sometimes they are intensely emotional choices. And I’ve always had a deep Romantic respect for emotion. My love for Louis transcends wisdom. And I may need the pain as much as the consolation that an eternal relationship with Louis would involve.“

5) I just posted a letter Anne Rice get from a queer fan who expressed how grateful he was to her for IWTV, and I don’t want to attempt to summarize it for you, please read it to see his perspective for yourself, even though he does not specifically mention Louis/Lestat as a ship.

6) Anne Rice gets this question on a regular basis. I don’t know if her answer below convinced the commenter, Romeo Naghdi, that Lestat is “totally bisexual, totally omni sexual” (which was another term for bisexual some years ago, IIRC). To be honest, I think when she answers these types of questions she is answering so that others can see her statement, even if the commenter might remain steadfast in their own opinion.

[^X 6/26/2015]  ^Personally, I don’t know how Romeo Naghdi (and others who share his opinion) read the same books that I/we did, but I don’t care what he thinks of Lestat’s sexuality, and I would encourage you all to go with Anne Rice on this. She made her statement and then let it go. 

I am not attempting to erase any queer representation in mentioning that we have these people who headcanon Lestat as straight. I included it only to give the context to AR’s comment. 

I hope that helps, Anon! Again, anyone is welcome to reblog/comment on this as to why they ship Louis/Lestat, even though they “absolutely hate and insult each other” during IWTV!