my ipad has a blue line that flows across the screen from one side to the other. sometimes it kicks me off.

I had my 1st iphone 4s, I then bought an ipad 2, i used the same apple id, my yahoo account for both devices. I returned my iphone because it wasnt holding a charge and was freezing up. I got a new iphone 4s and set it up with a different I cloud email. Because I didnt want anyone reading emails send between my husband and my self showing up on my ipad for everyone to see.

Now im having issues on both devices saying error please enter your apple password for this adress. but it wont eccept my apple id and this message pops up frenquently on both devices.

Also I hooked my ipad up to my cannon Rebel, so that pics would pop up on the ipad screen that way I could make sure the pics came out looking decent.

But they never popped upon my ipad they just loaded them all on there. and now I have a thick blue line that moves back and forth my ipad screen.

I dont like the IOS 7 update on my Iphone. it doesnt work as goo. I want to remove it.

please tell me how to solve these 4 issues.

1) ipad & iphone to accept my passwords?

2) get ride of the blue line that sometomes kicks me off wifi or what ever im doing?

3) set up my ipad not to store the photos but to display them while hooked to my cannon rebel camera, while i shoot pics?

4) Remove IOS 7 from my iphone

Thank you

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