Is the kinetic energy in the stream making the water flow uphill analogous to negentropy in a closed system? If so therefore are creationists trying to deny that negentropy occurs?
As noted in the very first link of the topic the term negentropy isn't necessary. Thermodynamics always as talked about entropy both increasing
and decreasing. We don't need the new term.
Yes, the water flowing up hill strikes me as a good analogy. It is also pointing out that even in a closed system there can be local decreases in entropy even if the total entropy must increase.
If so therefore are creationists trying to deny that negentropy occurs?
Who knows what creationists are claiming? They change a lot. However, if creationists try to say that the 2nd law forbids evolution then they are, in fact, saying that local decreases in entropy are not possible or that entropy can't decrease in an open system.
They are, in affect, saying that the water can not swirl uphill in the steam analogy.
What you link to aig does is manage to confuse some things. For one thing they correctly point out that even if evolution is shown to be correct and to not violate any thermodynamic considerations that doesn't tell us about the origin of life. I agree with that. However, since they don't agree with evolution why would they muddle up the two here?
Then they get onto the "information" issue. That has been thrashed out here a few times. They are focussing on mutations and forgetting about selection yet again. One thing that never seems to be "gotten" is that to argue with an idea, especially one as broadly supported and as detailed as the ToE, you have to understand it very well indeed. They don't.