What does it matter, just do a new game plus.
Why play the game though twice when you can play it once and get it finished with? :-D

As for that guide, I actually went back to gameFAQs and got that guide before even reading this thread again. I restarted my game and am now at 68%. It's a great guide, very precise. I just wanna know, do you have to beat Trema to get 100% or just get the spheres in Via Infinito? Cos I think you could only get those high levels on a new game plus unless you spend hours and hours fighting in your first play-through.