It will slightly go down I think. The recent price rally and stability in $5500 range may be caused by people who bought BTC in order to get free BCG fork coin. After holding those BTC, people may dump it back and causing a slight downward movement.

Answer to 2nd question, yes. I personally think that holding BTC is always a good move for the long term. I've proved that so far. So, hold those BTC and sell BTG for free BTC as soon as possible