1-Most of the akatsuki weren't villainous(in terms of their action, most of them weren;t motivated out pure evilness),Being evil was never a requirement nor a quality for being a member. Plus if you're making this point, then you might as well apply it to itachi and nagato.
2-Lmao half of the akatsuki failed in multiple missions
3-What did zetsu or hidan and kakazu do? what about sasori?
4-she actually is in contrast to other ninja. Plus in angle mode she is untouchable by most people , that's hax with enough chakra.
5-Yahiko killed his own damn self, and again, all of the akatsuki failed at some of their missions.
6-Her motivates or dreams were never mentioned or hinted in the manga and that was due to bad writing. But her doing what nagato wanted is merely nothing but the mix of respect to yahiko's legacy+being part of the akatsuki+supporting a friend.