Will Apple find out about my jailbreak?

I jail-broke my iphone (4S) 3 months ago and now my power button is broken. I can't click it so now my phone isn't able to lock (unless I leave it untouched) and turn off. My insurance warranty is still on so I could be able to fix it. So if I restore my phone and give it to Apple. Will they find out? And I also have some scratches on the sides and corners on my phone, will they be able to fix the power button and the scratches? And if I tell them about the power button, and they see the scratches and stuff, will they just fix it by themselves without me telling them or what. LOL. And how much is the insurance again? I kinda forgot. I have sprint.

Restore will remove the jailbreak and they will not find out.

Apple can tell a iphone was jailbroke in 2 seconds.
also no matter how many times you restore, there are files that the jailbreak add that can't be removed.
warranty is void, buy a new iphone