In any case, it is not always necessary to sell coins at low prices. And first of all it depends on the real prospects of the project and how the team works.
Not necessary if you believe that the project is so good. But if it isn't, you should start considering of selling that and move to a better coin as an investment before your money is gone. That's how you take if you value the coin that you have, you need to sell at loss and recover in some other coins or sell if you are contented with it.
The goal of keeping is trusting the project to bring best outcome to your investment, if you don't find that from what you are holding and you already losing your trust to such project, best to sell it out with loses and try your luck to find another one which you think can give you benefits to recover or to earned more, cutting your losses and try to work it out to another assets is a diversion you only need to understand that you should not make the same mistake again when you pick another project to invest your money.
Nothing wrong if you are selling these tokens since you just took them from bounties. I guess that most of the bounty tokens are hard to dispose because of too much belief that they will moon, you have difficulties of selling them.