Some trader that based on pure technical analysis, usually they will stay away from the market if there are news high impact will released, because often making pair move uncertainty, often occur after move down rapidly then suddenly move to uptrend with large pips also.
If you don't understand the outcome of any high impact news then you should close your positions. Its best not to lose any profit that market is offering you.
Well sometimes the market don't bother about any news and continue its movement. In this case you will be repenting on closing your position. So best option is that you should close half your position, set the other to break even and let it run.
That's true, but you never know which one it will be, so it's better to be careful. One could, as you said, close half their position and continue with the rest, but that depends on how large your account is.
And sometimes even if you do understand the outcome the price can still move the opposite way you expected as the same news outcome may have already been priced in.If you don't understand the outcome of any high impact news then you should close your positions. Its best not to lose any profit that market is offering you.