Regarding the animation speed:
If you don't want to remap the animation, the map used within Forest Pack's Animation rollout shouldn't be animated - as this way values are changing during the time and it causes, that the animation will follow actual map values. Unfortunately there is no way how to avoid this behaviour.
To get something similar you could use "Random from Map" animation mode instead of "Frame from Map", as this uses a map to define the absolute frame within a Start/End range.
The "Random from Map" option works similar to Random Samples, but using a map to define what animation sample to get for each item.
For example, by setting Samples=4, Time=10, a black pixel in the map will take an animation sample at frame 0, a white pixel at frame 30, and interpolated samples for pixels in the grayscale range. The UV coordinates are taken from the surface assigned in the Surfaces rollout.
If you will move the animation start of your object from frame 0 towards (for example 50) this way you can offset the animation start.
Hope it helps you.