There could be many reasons. Maybe he was in a dangerous situation inside, like a fire or an attack. Another possibility is that he was experiencing some mental distress, such as depression or extreme anxiety.
Definitely not. Even though the second story might seem relatively low compared to higher floors, the impact of hitting the ground can still be severe. There's a high risk of fractures in the legs, arms, or spine. And there could also be potential life - threatening injuries to the head or vital organs.
In Jin Yong's martial arts novels, jumping off a cliff was a common scene. Xiao Yuanshan and Duan Yu both jumped off a cliff in Demigods. In order to escape the siege, Xiao Yuanshan was saved by a branch after jumping off the cliff, while Duan Yu accidentally fell off the cliff while escaping the pursuit. These scenes of jumping off the cliff played a role in promoting the development of the plot in Jin Yong's novels. Apart from Jin Yong's works, other martial arts novels also had scenes of jumping off cliffs, such as The Legend of the White-Haired Witch and The Smiling Proud Jianghu. In these novels, the main characters often jumped off cliffs in order to seek martial arts manuals or escape from being hunted. In general, jumping off a cliff was one of the common plots in martial arts novels. By jumping off a cliff, the protagonist could often obtain a fortuitous encounter, change his fate, or achieve revenge.
You can't survive. A 5-story drop is way too high. The force of the landing would cause massive trauma to your body, and it's very unlikely you'd make it out alive.