· Is it difficult to remove the car docking sled? For instance, to install the tuner or move to another car?
It's no more difficult to remove the sled than it was to install it in the first place.
If you installed it yourself, then you already know what's involved to remove it. The hard part is usually the wiring connections. The sled itself usually just involves bending out the tabs and removing it.
If you had a professional install it, then you should probably have a professional do the moving/removing work.