Although you can use it without a case, it’s a good idea to purchase some kind of case and a screen protector. All iPhones use glass screens that can break if dropped.
There a 3 ways in order to make payment:
Yes. You will need to download and install the Windows Support Software using the Boot Camp Assistant to use the Retina display with Windows 7 and 8.
The screen repair can take up to 24hours depending on the device, but this may be determined by stock availability and the demand at specific stores.
The Touchpad and LCD are merged together, so if the one breaks both need to be replaced.
This will all depend on what type of device you have and what part on that device has to be repaired. The repair times vary, from 20min to 45min for a basic screen and battery repair, and then to a day or more for labour-intensive repairs.