Yes its risky even if the bitcoin has a lot of potential. Invest only what you can afford to loose, because if you invest all of your money you will get to emotional when the price drops.
Nope., I don't think so, if you really an open minded then their is no worry or doubts to invest all your money in bitcoin. Because even bitcoin suddenly drop but when it will go high it's much more increase irs value that's we called bitcoin is volatile.
Well yes but the problem is that if he puts all of his money in bitcoin he's risking to pull that money out in case he needs it and at that time, bitcoin price may be significantly lower, it's better so save something on the side just on case because you can never know what can happen tomorrow.