i think it is not such a difficult job you can do it very simply, you can exchange bitcoin into your local currency in exchange and then can also buy bitcoin if you feel that it is the good time to do so.
Yes , but it has a risk behind them . Especially you sell it in online sites , who knows you would be get scammed or it's just fake sites to stealing your money . But , as long as you sell it in the right place and has a good reputation you should be fine .