Ah to each their own eh... as many, I can't decide. I like the sad, melancholic Yuna, but I wouldn't have like dif she STILL was sad melancholic two years after savibg the world. She changed, as people tend to. The new outfit fits her new lease on life. A summoner's robe would be out of character for her now...

Regarding the 'where did she learn to us ethem'... well.... I understood that the Dress-Sphere's give the abilities, so without the dress-sphere, Yuna might indeed be unable to properly aim a gun...

But I'd file that under 'it's a game. Don't think about it'