I want to register a domain name like "pokestopclub.com". I think PokemonGo is registered trademark, but the term "pokestop" is not. Can I legally use "pokestopclub.com" for a commercial social network where people will share info about PokemonGo Pokestops and Events involving PokemonGo games? If I include Obvious Signs indicating NO Official Connection with PokemonGo trademark owners will I reduce chances of litigation?
There is law called Anticybersquatting Consumer Protection Act that regulates this. For your specific case, this probably would fall into the same cases as priuschat.com or windowsforum.com where you would be doing "fair use" of the trademark. I can't tell if including obvious signs of unaffiliation would help in anyway, but using their logos and trademarks outside of the "fair use" clause could very likely bring you trouble. Take a look in the websites that I cited above and you will see that they are quite careful in resembling their subjects but avoiding using any of the trademarked logos. Deducing by their ads, those websites are definitively commercial and sometimes the trademark owners even sponsor then. I heard once that Microsoft distributed free licenses to the owners of some Windows forums, but I can't remember the source now.