Apart from the design difference - the biggest difference is AirPods are wireless while EarPods are not wireless. The AirPods comes with lot more openings compared to EarPods.
Yes, you can use Airpods with iPhone 7.
Yes. Airpods will work in the same capacity as EarPods.
Absolutely fantastic. You will also get slight more bass when you listen to music.
If you have already paired your AirPords with your iPhone and want to pair with any other iPhone, you need to follow the below steps.
Step 1: Open your AirPods charging case
Step 2: Tap "Connect"
Step 3: Press and hold the "pairing" button on the back of the case.
Look past their offbeat design and you'll find that Apple AirPods' compact size and high convenience factor are a winning combination.