Some simple question

I believe that Kimsufi/OVH verifies IDs in many cases and doesn't accept orders under 18.

 

You can use your passport and a letter (phone bill, rent etc) to verify your identity and address. I personally used my Driving License once and phone bill and Passport + Phone bill for my second account.

 

You could fake your age, but make sure all the other information is true.

 

You can but that's technically not legal so don't get mad if they find out and cancel you.