I think you need to either read a full plot summary, or just bite the bullet and finish the game because a lot of the story you don't have straight just yet. After you get to Zanarkand and go through the cloister of trials there, what Sin is, how it comes to be, and what its purpose is becomes clear. And then EVERYTHING becomes clear after all that and you visit Maester Mika again.bartholen said:-snip-
Also, to save yourself a lot of grief, I would just look up a guide when you fight the boss battles in Zanarkand. There's one right after you complete the cloister of trials that isn't so bad once you figure out his pattern, but there's another after that one that is a total ***** if you don't go in with a plan.
I like the game more or less, but don't get me wrong, a lot of what bothers you bothers me too. Especially what you said about the timetable of when Summoners work. Once you find out what the Fayth really are and how they work, then your idea of the Summoners completing the pilgrimage during the calm makes a hell of a lot more sense. Also, I hate how they never explain why Tidus, Rikku, and Wakka can hold their breath underwater for so long. Apparently the others can't because when you have to do water sequences it's always them and never others, so it just doesn't make sense. Tidus is annoying but so are most young male protagonists from Japan, and they all dress funny because it's Squaresoft (they weren't Square Enix just yet when it came out).
Oh, and if you get passed Zanarkand, you can get Anima as a summon. You have to get the destruction spheres in all the cloister of trials in order to get him, but don't worry. If you missed any you are free to go back and get them after Zanarkand (but don't worry about Bevelle, you have to use that destruction sphere to get out of there, so even if you didn't get to the treasure chest it will still be complete). Look up a guide for that, as well. I recommend this not only because she's a cool and powerful aeon (yes, she), but also because there's a bit of story tied to her that I found really interesting and sad.