The first depends on your own choice, if you want to invest in the long run, of course you should be able to be patient waiting for the price of coins for a long time or at least until the price actually increases. different from the short term you can easily get short profits but very high risk.
Long term and short term both are high risk but this depends on how the traders will employ his strategy.
There's no one prove that short term is less risky that long term because at the end of the game, we are just all gambling with the prediction game.
if you are not good enough to do short term, then long term will best suit of you as its simple to do, it's just a buy, hold, then sell at the right time.
However, there are also times that our target will not happen even if we hold for a very long period already, that's where we will have to evaluate everything if we can still continue to hold.
Exactly, I even only held bitcoin and ethereum. I don't know yet whether I will hold back for a long time, or not, but I might see the situation. if the price goes up in the near future, and on target, I will certainly sell it, but if not, I might continue to hold it in the long run.
Well, this only applies to popular coins. if you hold altcoin below the top 50 coins, I'm afraid the price will go down if there is no progress and is held for a long period of time.