Toge Inumaki is important too. His special cursed speech ability makes him stand out. Also, the principal of the school, Masamichi Yaga, is likely to be important as he is in a position of authority and has an influence on Gojo and the other students. There could be other characters like the members of different clans that also play roles in the complex web of the story.
It depends on various factors. If the man is well - trained in rigging techniques and has the proper equipment, it can be relatively safe. However, without the right knowledge and safety measures, it can be extremely dangerous as rigging to the second story involves height risks, potential equipment failures, and the need for precise calculations.
Always swim in areas supervised by lifeguards. They are trained to handle emergencies and can quickly come to your aid if something goes wrong. Pay attention to the warning flags on the beach - red flags usually mean dangerous conditions and it's best not to swim. Also, apply sunscreen regularly to protect your skin from the sun's harmful rays.