On the part talking about her powers it states that her telepathic abilities are suppressed while in her diamond state and in two seperate issues one being New X-Men and Astonishing X-Men, Emma uses her telepathic powers while in diamond form. It was issue 5 of Astonishing and issue 150 of New X-men. I don't know if this is a mistake or if you mean she has limited telepathic abilites. I was just wondering.
In New X-Men after Emma's diamond form was shattered, Bishop & Beast said that she possessed a flaw in her diamond form, then in Astonishing X-Men the former Danger Room, now called Danger, said that she does not have any flaw in her diamond form. I think that when Jean Grey/Phoenix fused her fragmented diamond form back together she (Jean Grey) removed the flaw.
Also, some sources state that she gains no increase in strength when she becomes diamond, yet other sources say that she can lift between 25 and 75 tons. I think she does have super-human strength, like when Colossus transforms to steel.