I dont pay attention to game reporters because i prefer to see by muself if it is possible for me to like a game . But if you are a good professional you will avoid beeing biased , it all depends on the professionalism of the individual :)
Freelancing could work as a side job. But you get your biases while in the biz and that could effect one's journalistic integrity. But then again no one should have die hard readers that only listen to the articles of one journalist, especially for determining if one likes a game, I would argue the ethics a bit on that.
The thing is i doubt developers would give or let you play preview copies of their games if you were working for competition. Also game publications allready have a pretty bad name for biased reviews so i doubt they would want to make it even worse by hiring someone from the industry. I guess you could write about how the…