Ok I have 2 questions:: 1) The first time I played I got to Macalania..

Question for Final Fantasy X

Ok I have 2 questions::
1) The first time I played I got to Macalania right before beating Seymour and on the Al Bhed machina I rode with Rikku. But the second time I rode with Lulu. How did this happen?
2) The first time near Djose when you beat Sinspawn after Mi'ihen Highroad then I found the dark haired Crusader and he all "WHATS GOING ON??" and when I got to the temple he told me the redhead died. But the second time around tidus found the dark haired one and tidus was all, "Wake up..." but he was dead and when I went to the temple the redhead was like cursing and having a fit becuase the dark short one died. Please explain??? And please also tell me who is who?
Thank you so much
~*me*~