
It's cute to see that arwin and latte are still a dorky couple and in love more than ever....I just need more pleaaaaaase (/ω\)
who's bishot's wife is it esula??? What about ibelin?the prince?kenneth?the princess?? I need moooore I enjoyed this so much maybe that's why I can't let go of this novel

So
1) yes Bishot wife is Esula and a part of the side story is actually about Latte and Arwin's son, and Esula's daughter, who will become a couple.
2-3) As you said, Ibelin and the prince marry each other, but the prince finally feels like Arwin and Kenneth, and don't love Ibelin anymore. He is a trash and superficial, and even if he takes Ibelin as his queen he will not make her his empress because he is tired of her. She will have to bear his son to have his attention back.
Don't remember in the detail but he lets her alone and is a bit the trashy dude (not like in the webtoon). There is a moment where he sees a maid with blond hair, and it reminds him stg funny and nostalgic but actually he can't say it reminds him latte since he became such a trash that I've read Arwin erases his memories of Latte at the end of the story (I quite liked this character so I prefer to think of him in the webtoon as another one)
Ibelin is happy as a mother I guess, now she has a baby and the prince's attention comes back a bit.
4) Kenneth finds love ! I'm so happy for him ! Thanks to Latte's help with the new law he is not harrassed anymore, and he goes to fulfill a promess he did with an elder knight who died, which was to protect his daughter. They fall in love, and they marry. Latte is at the wedding, and Kenneth and Latte stay best Friends until the end of the story.
5) the princess becomes a famous Bl writer. I don't know if she is with someone, but she is happy with her dreams and passions, this is a good ending for her !

I don't know sorry I've just read spoilers here https://forum.novelupdates.com/threads/miss-not-so-sidekick.81455/
If you want to look (there are 42 pages so I dont exactly where I've read about the side story but this is in this forum)

When she said to eclipse that clea is dead i feel something in the pit of my stomach. Mc is right eclipse blamed clea for everything bcs that's the only way he can cope with his loss (although I don't like it) so i feel pity for him since i know eclipse kinda expects that her sister will always be there on her evil glory so his chance to patch things up with her real sister is already over.
He's just so perfect.....
Someone please link up the novel if this have one
Sorry mistakenly disliked