Long term investments are generaly always risky because you can predict so far in the future what will happen. But to my opinion Bitcoin is worth that risk and it's most profitable long term. Sometimes when the dumps are big it's a bit hard to keep the cool head and try to be reasonable but with experience is easier.
No; usually long term investments are less risky than short term ones. Of course always there is risk but it is low, mid and high risk and profit is depending on risk. Say that somebody buy stocks that tend to grow slowly. These stocks tend to be less volatile, that is less risky, because the underlying company has steady but not spectacular growth. Which of next two is more risky? Buying stocks from a wordwide known bank or from a startup company?