Huh, you're right, they do. I could have sworn I'd missed at least once in a while with Squall back in the day.. my memories going bad, I guess.
It's still up to debate which system to use... I feel like the fairest would be using IX's, because it's the game in the middle But claiming either needs to use the system of the other (or needs to evade or defend by the rules of the other) seems like favoring one.
But yes, the Status attacks, especially Death and Stone because they ignore Ribbon are pretty bad for Tidus.
Why would you want Auto-Life (assuming you mean Auto-Pheonix because Auto-Life as far as i recall doesn't exist as an ability)? I mean, I know we said no prep-time but Auto-Life is a total waste of a space Tidus really needs after we considered Squall's deadly status attacks.