Random Battles are not that bad...it helps alot in leveling up aka Yuna in X-
The things that should never come back are:

X-Auto Life on the final boss.....you work so hard at getting there and well don't need to say more...
X-2.....monkey breeding mini game...how does that help you....... at all.
IX-Trance just to soon before boss....
X-2..Gunners Gaunlet mini game....I hated re-doing it with my record
VII-No good place to level up...
IX- so what is this Crystal thing you keep saying.... and who is Necron. I thought Kuja was the bad guy..lol

Over all thats it but I am still a Die Hard FF Fan n_n