Well, Omni Man does die in the comics. The reasons behind it involve various plot developments and character interactions that shape the course of the story. It's a pivotal moment that changes the dynamics of the comic world.
Hard to tell exactly. It might have been a case of temporary insanity, or maybe the son did something that the father perceived as unforgivable. We'd need more context to understand this awful event.
Well, the death of Omni Man in the comics is a complex and intense event. It involves a series of conflicts and plot twists that lead to his ultimate fate. It's too detailed to explain briefly here. You really need to read it to get the full impact.
Sure. Invincible's journey in the comics sees him continuously evolving and getting stronger. Eventually, he outpaces Omni-Man, but it's not an easy or straightforward path. There are many challenges and setbacks along the way.