I think so. With so many new cryptocurrencis in the market today, it is very posible that eventually bitcoin will die out if this trends continues. 

Yes.
In fact it did after hitting an all time high last 2013 and the price went slowly glidding down before souring up again. 

Used to gamble with bitcoins during the faucet frenzy years of bitcoin when the prices was just so low (about two years ago). The difficult thing there is when to stop and make sure you already won enough than what you lost. 

How much risk in bitcoin investement ?

It depends upon the condition of the bitcoin market.
There are a lot of bitcoin earning schemes in the internet today. The problem really is where to start and where to invest.
When I started studying about bitcoin, it was only sold for $297.94. Today the price is almost 10 times to when I started to know about Bitcoin. Who knows what the price will be two years from now.