I could give you tips like the others, but I would ask: what is the point of what you're doing? It seems that you've already cheated to gain progress so its not completing the story. The obvious reason would be to complete the game without cheating; but at the same time you're asking for an easy way to do that - isn't the idea to gain satisfaction through overcoming difficulties?

I admit there was an occasion where I was seduced into trying the Don Tonberry trick mentioned above. I've never gone back to that save since, because it took away a lot of the meaning of the game. Some tips may not technically be cheating but just ruin everything.

Hope you take this in a good way as friendly advice to be careful which tips you follow. Its not that hard to complete the main storyline anyway.