http://www.domainsherpa.com/6-ways-to-recover-a-domain-name-from-an-infringing-cybersquatter/
This happened to a friend of mine who own a "Hotmail" domain and Microsoft got it within a few weeks and he walked away with $0.
But, i am not sure if domains such as gmaio.com are allowed. Anyone knows?
Gmail could be taken only if the website is related to gmail in any way like a phishing site or a clone. If its just a normal random site it would be fine because trademarks don't cover mis spellings unless its meant to distract or confuse customers
Yep it's a case by case basis. Obviously if you're trying to steal customers it's copyright infringement. Coinbase is an actual blockchain term so if you use it for anything to do with bitcoins that isn't an exchange you aren't infringing on any copyright.