It's safe to assume so because he was one of the youngest and he had a iffy mental state, he would have be already lost his mind and probably would have done suicide without the wills/wishes
Yes, seeing as how he was the youngest and the one that was literally teetering on suicide after losing his friend. You can tell from how all of them worried and fussed over the 2 youngest people and tried protecting them.
That was their way of not allowing him to die like them, all of them knew that once they were out that they would mostly likely commit suicide. That's why they would write down their wills and why they gave him ridiculous request when on their death bed. It was to give him enough time to somehow find a way to keep going.
That's how i saw it anyway idk.
Yup. That's explained more explicitly in the novel
Did everyone starts bombing seo(MC) with insane amount of wishes because of his state? They knew he would himself once they cleared the dungeon. Was that their way of stopping him?