>>299807479
as for the first part of your question, you either weight painted it wrong or didn't parent the bone right. For this you can literally just do the floor slime part separately and add it in in unity, under the armature so it's always under you.

for the second part, I'm not that familiar with arktoons, but you have the right idea with using a watery normal map to scroll to simulate slime undulation. Not sure of any shaders that have both refraction and norm+panning