A great deal of it is about choice. We are a species with the ability to make choices and up to a point we have the free-will to do this. People don't 'turn' good or bad when faced with a series of choices. They base what they are going to do on the information they have at their disposal at THAT moment in time. Every single human being has the capacity for great deeds of goodness, but we also each have the capacity for horrific deeds too. Its the circumstances at the time which dictate which path you'll walk down.
One of the points made in this episode was that we can 'choose' to take a different path, but we'll only do so if the information which influences us to take that path is freely available to us. Shifu showed Daniel the possible outcome and the effect it COULD have on his personality and the extreme consequences to the world and those around him IF he went down the path of 'absolute power'. If you don't have the necessary information to hand about what will happen if you do make this decision or that decision, then it's easy to think that what you are doing is for the benefit of all. It's easy to kid yourself that its the right path for everyone.
But it's very true that generally we don't have the benefit of Shifu character on hand to show us what will happen when we make life altering decisions, mostly we make them blind based on what is right for us and then hope that it'll all work out just fine.
Because Daniel had asked him to help them and give them the information he had within the genetic knowledge of the Harcesis I would guess that Shifu was trying to show him that even if he did help and tell the humans what they wanted to know, there are still consequences from any decision that is made based on that information which need to be considered. For every action taken, there is an equal and positive reaction.
While it's true that he who hesitates is lost, you should always look before you leap!