I guess Alkanese is using a hammer? The thing about those is that they're unique in that they will always have a miss chance of 25% added to them, even if you have 200 accuracy. I guess the devs wanted to offset the power of hammers, f.i. by stunning every enemy on the battlefield at once with the risk of missing occasionally. For what it's worth, all other weapons work straight forward as you expect them to, so max accuracy on a sword user will mean they won't ever miss. Unless they're attacking a flying enemy, heh.
Noir's rumor is just like any other one of Crane's rumors, random. Since you can recruit Noir during one of Lia's missions with or without the rumor, it's definitely more likely that the rumors are just meant to tell you what to do and they're not technically necessary to recruit the girls.