Living in the UK you do need license to buy Airsoft replicas that are fully black and must be over 18 to get what they call UKARA license.
You must play three games in the span of two months and have a form of identfication to prove your 18. (Passport or Driving license).
yes airsoft guns are legal in OHIO
Yes, airsoft guns are legal in Canada.
Usually airsoft guns aren't allowed in public places
Yes
Yes
Yes, they are.
Yes
Yes they are.
18 in the USA
Yes, i'm 14 and i own 4 airsoft guns.. As long as its on your property and not like in a city
Yes, they're legal in all states.
I don't know about Canadian airsoft stores, but I know that most airsoft in North America sell Canadian-legal airsoft guns.