Why is it so difficult to play SFC version of Fire Jihad bloodline with PSP? ....

You have no ability to practice writing. Save characters before upgrading. When upgrading, add less, such as HP+ 1, and it will drop. Reading files, changing the battle order or upgrading order, or leaving a heavy armor in the city fighting skill field will change the points added when upgrading. As for the ranks, the pirates in Chapter III and the flying horse in Chapter IV will return to the city indefinitely and practice their ranks easily as long as they don't kill the commanders. In the first half, try to match all the women with marriage partners, so that the children in the second half will be strong.