ipad repairing screen questions?

2a. I would recommend referencing the guides in part 5 of this answer to see what parts you need.

2b. There are no kits made by Apple for you to repair your device. Apple would rather have you take the device to an Apple Store or Apple-Authorized repair center, or better yet, buy a new device. This makes them more money and/or allows them to limit what repairs the repair centers can do.

3.The quality of displays used by repair shops vary. Keep in mind that lots of repair shops would like to use new Apple genuine screens, but Apple will not sell genuine parts to any non-Apple Certified repair centers(Same reason as stated in 2b).

5.I would recommend the iFixit guides for replacing the screen and digitizer.

7.A cracked screen can send incorrect touch inputs to the iPad logic board, making the iPad go haywire.