Those are some hard challenges but they are not the hardest. These 3 would have to be the hardest challenges possible.....

No Summon/S.Grid/Customization Challenge
http://db.gamefaqs.com/console/ps2/f...ere_custom.txt

No Summon/Sphere Grid/Overdrive Challenge
http://db.gamefaqs.com/console/ps2/f..._x_nsnsgno.txt

No Sphere Grid Monster Arena
http://db.gamefaqs.com/console/ps2/f...grid_arena.txt

I have never completed these challenges and I never will try. But if you think you are a FFX master then give them a try. I posted some walkthroughs for them from the Gamefaqs message board. Have fun.