Just downloaded the international version.
I played it once, but dropped at the end because the disc was fucked up.
Any tips about missables, grid and stuff?
The Jech Shot is the only missable skill that really makes the difference (you can gain it at the ship near beginning by doing the button-combo sequence correctly).
Spam it at the Blizball game, and you'll pretty much win automatically.
Also try to finish those Faith cloisters fully before moving forward, and look up that stupid dog in the Besaid island.
you can even win the first tournament game, though it really does nothing except shows the Besaid Aurochs with a big ass trophy, I don't recall it doing anything else for the story
Grind is unnecessary, just never run from battles and make sure everyone participates and you should be the appropriate level for everything.
Try and get nuldeath equipment for before the end of the zanarkand section, or yunalesca can 1shot your entire party.
Make sure you get the secret item in every cloister of trials, or you won't be able to unlock the super powerful summons, making the postgame nigh impossible.
It's not worth getting Lulu's celestial weapon, but definitely get Yuna's.
expert has less total spheres if you are going for the trophy to fill out grids. rearranges the grid a bit. you can unlock better shit quicker if you know where you are going. very easy to open up steal and use commands early and shit on everything with petrify grenades. can teach everyone esuna and cure quick. can get hp spheres early from that plant guy (lord morbo? something like that) and because all start in mid, they can all just immediately gain about 900 hp (you get 1 hp sphere in a chest i think and can overkill for 2 from the plant boss for 900 total. that early in game makes rest cake walk. can get yuna some combat spells as well very early making her useful.