Actually no, he is just The Architect of the System, but the System will survive and maintain itself functioning even without him.
Uhh I think no? Because he only made Jinwoo see all those window stuff (idk what it's called) and told him to do those things. He lowkey helped Jinwoo get stronger. So I guess you're kinda right that the gate is gonna disappear since Jinwoo defeated the God dude
Indeed, just like someone built a city, after they die the city will still be there
If you kill that God, the simulation ends right? Including gates,monsters or stuff right?