I did it, I fucking did it! Took me all year but I finally did it!
I completed 100% the game on HARD on my first playthrough.
Let me tell you the hardest part was the Wutai castle in the beginning with the stars. The problem is there's really no easy way for you to level up, there are no save points and if you die you have to watch a 5 min unskiappable cutscene to get back into the action. After that there may have been a few close calls, but that part really had me wanting to restart on normal.
I finished 100% of the missions, got all the genji armor, got 100% of the DMWs.
Genji shield was the one I thought I would have to skip. The requirements seemed like waaay too much luck but I thought what the hell I'll give it a shot - once I had all my equipment set up I got it on the first attempt!
Super game IMO. I don't know what it was about the missions but I was addicted to them. I think it had to do with how they each demanded different skills. Some where high magic enemies, some where status dealing monsters, etc. It was always a new challenge to try. I put 15-30 mins a day almost every weekday until I finished all 300 damn missions.