This mod makes the scale of the game feel much more normal. Since he now takes smaller steps, but still runs at the same speed, his feet "skate" along the ground which looks odd. Either reducing the running speed or speeding up the running animation would fix this.
Edit: Easy change. Change animation_speed from 0.6 to 0.857 for any animation with "running" in the name to make his feet match the ground.
Also in your data.lua file you can delete everything in the "playeranimations =" section. This is redundant since this information is also contained in demo-player-animations.lua