You can never lose if you sell at a profit. This can be potentially bad advice. you can lose if you never sell in the potential case that bitcoin crashes to 1000 and you bought at 2000. its going to be a rough trip emotionally for you if it does. dont be so blind and follow the hype. making safer decisions is always better than taking unnecessary risk.
That's correct, however we want to earn more and at this very moment it is not advisable to sell bitcoin to gain more.
When there is a pump, it's time to hold and you sell it when it starts to dump.
Don't wait for your altcoins ro dump before you sell it. If it starts to dump, just hold it as it could try breaking its resistance which can lead you more profit if you prefer to hold. Just place your exit point in a loing where in it doesn't dumps so that there is no devalue in your money.