That's a good one. But without knowing your setup it's almost impossible to tell a good one. For me a good one is: leave when happens strong divergences in strength and volume, and price is way to far from a MA(200) and it's outside of the bands (keltner).
If you want to share some of your way to enter I can help you to find a good way to leave the operation.
I don't think it matters.
The longer you are in the trend, the more play you will have on your stop.
When you observe that it is running out of steam or moving closer to possible reversal point, its possible to move the stop real close.
Because otherwise you would still only end up with about half of the move on it's way back.
I guess it's the art of trading.
This will never yield the same numbers.
Actually it doesn't have to take much time at all.
If it does with you, then maybe you don't know how to do it accurately.