1. Yes, in order to get strongest weapon, u must get a set of item and sell to the shop in order to gte the weapon, these kind of item is hard to get. Besides this, there still got a lot quest to do, depend on the level the quest u do, more high lv, more hard.

Some weapon like Zodiac Spear, u ned to open treasure chest to get it, therefore, not 100% u will get it, u ned to equip a ring(to get good item) and u got a low chance to get....(below 10%), and the treasure chest not everytimes apper also. Some treasure chest only apper 1 times, after u open then it wont appear anymore.

2. Weapon i dunno, but the summon already is stronge monster already, u can get 4 or 5 summon according to the walkthrough, other u must do the quest and defeat it (in order to gte summon, u must fight with it 1st). Besides this, still got other stronge monster that u ned to fight for doing quest. There got rare monster also that appear when the requirement is meet like weather or else...

3. what world map u mean? world map is sure got , just a piece of paper XD, if u say the world like FF 7,8,9 , the answer is no, FF XII like FFX , no worldmaps

4.Haha, quite long, i play 30 hour already, in the half way, the percent of quest that i had done not over 20%(all i done is easy quest). I think is quite long to do all the quest.

5.Depends

6.The background music.... different from previous FF, because not Umeatsu compose, the background music is like online game's music.