Hey @MisuLikesDuxZ!
So for the MF_DynamicSCurve node, it looks like that was custom made by the creator of the video- they state that it can be found in the sample project in the description.
For the “X” thing you mean the Log2? Right click out in the open and search “Logarithm” and click Log2.
The pink nodes are reroute nodes- they’re just there to save space and confusion. Like a teleporter of sorts.
Hope that helps!