I too have been asked many time to trade friend's money - never did. The extra burden is not worth the risk. If I'm good, I rather profit from my money, because the "trader manager fee" isn't worth it.
That's right, no matter how good you are in calculating profit and loss, it will still be a burden on your own for your trade and if your friend wants to get a profit in trading, then it's enough to give your input and other suggestions so they also have the courage to trade in its own way.
When you are trading with someone elses money, there is either an added stress or maybe you are even more free because you just do not care.
I mean trading someone elses' money should be a little bit more freeing because in the end they did trusted you and that means you must be decent, if they trusted you wrongly and you are not good at all and they are just idiots to trust you with their money, that is their problem and not yours. You should just trade however you want with it and do whatever you want with that money.
This is obviously not just right thing to do, definitely not right thing to do, but it is at least a bit decent thing to do considering we are talking about trading here and not life related thing, you are not giving them your kidney, you are just trading money and that's it.