I don't find the Cloister of Trials hard, none of them. And I don't consider the cactuar hunt a puzzle. What about playing a game with cactuars has to do with puzzles?

Cloister of trials ihate this puzzle. Macalania,bevelle and Zanarkand is hardest with destruction sphere is useful if you want anima summon

And cactuar hunt there s clue how to find cactuar around spira after that cactuar play hide n seek. Now this minigame Just run directly towards ( name cactuar )each time it turns to look away from you. Ten seconds is plenty of time. This side quests useful if you want celestial weapon for Rikku

Cactuar for me, the cloysters are not that difficult imho.

I remember there 1 puzzle in Al bhed hometown when attacking by guado and Yevon

There are two chests in that lower room, and there are two others in a room up at the top of the stairs. Missable once you enter the door beside the save point.

There 2 puzzle, Password and Quiz

The code is random

Inside chest is useful friend sphere and return sphere

You will need to translate the code from Al Bhed to Spiran to be able to open the chest.