xenoblade chronicles - how do you define "100%" this game?

[hd94]

in my second playthrough (new game+), i have FINALLY complete all side quest, level up to lv99, found all secret area and collectables.

i have 3 superbosses left to defeat, and few heart-to-heart (all my party members' affinity are at max, just lazy to do it)

now that i almost done what i want to do in this game, how do you guys actually define 100% this game? most of my skill are not max yet (damnnnnnnnnnnnnn those rare skill bookk!!!!!!), i was thinking about finding all the skill book but it is almost impossible -.-