1. I just use Steam overlay to take screenshots. Those are stored in the Steam folder for the app you're taking screenshots for. However, I take high-res screenshots ingame as well. Those are stored in your User profile\Pictures\Frontier folder.
2. Yes, you can configure the FoV to make the game render a wider angle out of your cockpit. You have the slider in the game options but that one goes only up to 65 (i think). For anything above that, you need to edit the XML file manually. Just make sure you back up the original if you mess something up.
You can find the file here: C:\Users\{Username}\AppData\Local\Frontier Developments\Elite Dangerous\Options\Graphics
Look for the <FOV> settings