Onedine

For now, it looks like the drama makers have put Soonrok's scenes from webtoon to Babi's scenes in the drama, so it's hard to say what character Sonrook will be in the drama. Some suspect that he may not be there, hence the director's words that season 2 will be different. I think he will, but may not be Yumi "love interest". We have to wait for what it will look like.

1. He and his girlfriend decided to abort her pregnancy, she claimed he forced it on her.
2. He dropped her after it and broke up with her on the phone.
3. She said he was talking badly about his colleagues, the director of drama sets and stuff like that.
3. When the case came to light, he hid for 3 days, then apologized to the productions he worked in, to the fans for his behavior and apologized to his ex-girlfriend.
4. He lost contracts in several films and several advertising contracts.

The concept of the second season is that in the opening episodes, viewers don't know what Babi feels in certain scenes and will know his feelings only after his cells appear. Hence the scenes that show Yumi's reactions more than his. I think it fits in with a typical Korean drama play with the theme of "mystery", only here it is about Babi's thoughts, not, for example, solving a murder mystery. It is difficult to get attached (or understand his behavior) to a character who, at this stage, is intentionally portrayed without his point of view.

Yes. Even season 2 actors said yes when asked.

During the press conference held on the 7th, director Lee Sang Yeop chose “Bobby’s charms” as the new charm unique to season two. “Jinyoung shows off his charm to the point where I wonder if there can be such a sweet guy,” he shared. “Bobby’s cells will appear, and new Yumi’s cells that didn’t appear in season 1 will also show up. The animated world (the brain) has also gotten grander.”
About the new attempts she had made for the new season, Kim Go Eun commented, “There is a new cell called ‘smooth.’ Yumi grows her hair out thanks to this cell. Also, in this season, Yumi makes a courageous choice. It’s a life-altering choice.”
She added, “Yumi’s Cells was written to root for Yumi. I wanted her to look like that. Bobby and Yumi’s romance is the main story. But I went beyond the fun and tried to focus on the process of how they grow to understand each other.”
Jinyoung shared, “The evaluations of Bobby will be divided into two – how he is in the first half and the second half.” He continued, “There are fans who are already familiar with the original webtoon, so it might be confusing. So I hope you see Bobby as a warm person in the beginning. You can enjoy the whirlwind in the latter half of the show. But in the beginning, I want you to feel the 3D version of Bobby.”
https://zapzee.net/2022/06/08/are-you-ready-for-kim-go-eun-and-jinyoungs-romance-in-yumis-cells-2/

During the press conference held on the 7th, director Lee Sang Yeop chose “Bobby’s charms” as the new charm unique to season two. “Jinyoung shows off his charm to the point where I wonder if there can be such a sweet guy,” he shared. “Bobby’s cells will appear, and new Yumi’s cells that didn’t appear in season 1 will also show up. The animated world (the brain) has also gotten grander.”
About the new attempts she had made for the new season, Kim Go Eun commented, “There is a new cell called ‘smooth.’ Yumi grows her hair out thanks to this cell. Also, in this season, Yumi makes a courageous choice. It’s a life-altering choice.”
She added, “Yumi’s Cells was written to root for Yumi. I wanted her to look like that. Bobby and Yumi’s romance is the main story. But I went beyond the fun and tried to focus on the process of how they grow to understand each other.”
Jinyoung shared, “The evaluations of Bobby will be divided into two – how he is in the first half and the second half.” He continued, “There are fans who are already familiar with the original webtoon, so it might be confusing. So I hope you see Bobby as a warm person in the beginning. You can enjoy the whirlwind in the latter half of the show. But in the beginning, I want you to feel the 3D version of Bobby.”
https://zapzee.net/2022/06/08/are-you-ready-for-kim-go-eun-and-jinyoungs-romance-in-yumis-cells-2/

The scenes from Yumi's wedding were filmed at the end of December so whoever became her husband, which was the webtoon finale, will be known at the end of Season 2, so Season 3 seems impossible as there is no more original material to adapt.

From what I read, the webtoon writer had a commission to write more webtoon chapters than he planned and found the story getting predictable, so he introduced the Soonrok character as Yumi's third love interest. So there was no big plan for who would become "Yumi's love of life", it was just about money. So the drama ending can be anything.

There was never information about the third season from the producer of the drama.

Probably not. The drama producers never promised season 3.

she killed herself

In my opinion, theoretically, you can skip the 1st season, because I think that at the beginning of the 2nd season there will be a kind of mini-summary of what happened with Yumi in the 1st season. If anyone is interested in Season 2, for example just because of Yumi's new relationship, you can start watching Season 1 from Episode 8 when Yoo Babi's character appears. But if anyone is interested in developing Yumi's character, Season 1 is interesting.

Beyond Evil, Confession, Duel, Justice, Kairos, Memorist, Stranger, Stranger 2, Taxi Driver, The Veil, Train, Tunnel, Zombie Detective

rather no, there is a lot of violence

The shooting for the 1st and 2nd season lasted from April to the end of December 2021. There is no information that production is planned for the third season. If that were the case, they would have filmed it immediately after shooting for the 2nd season. All actors have plans for many months ahead, and they wouldn't even have had time to film a season like this, if it had ever been planned.

yes

He is in the cast of Season 2.

I can't wait to see what season 2 will be like.

The main characters in the drama are the same age. People are making a fuss here, and they don't even know the details of the script.

The main characters in the drama are the same age. The actress is just playing a character older than herself. In "Our beloved summer" her character was also older than an actress is in real life.