Haven't played many sports, have you? Sports stuff can hurt. And inasmuch as blitzball consists of throwing a ball really fast--and through water, which makes it harder--I bet anyone who played much would be capable of doing some serious damage with a blitzball.

Admittedly, I wander through the game wondering where the archers are, since other long-range weapons are illegal and you've got to catch dinner somehow.

I like Lulu's dolls for the same reason dagas_isa mentioned. It's kind of sweet. Lulu's just full of contradictions like that.

Functionally, they're probably similar to Yuna's staves: they're nice, and probably make things easier, but they're not by any means necessary.