Paul these reasons are what has held me back from signing up to this scheme, there are other considerations like coning off and public liability, as most call outs seem to happen in the winter, after dark, and in the rain, as the owner usually only seeks help after a few hours trying to get going. Most MVs are green and low visibility.
When a professional recovery firm arrives the driver is usually deemed to be in charge and left to it, this may not be so in the amateur case when the stressed owner thinks he knows best, resulting in chaos.
Amongst mates who work well together it is probably OK, but I can see problems for the over enthusiastic and unwary, s*d's law rules!
Don't get me wrong, I would be happy to help but for the above points.
Just my point of view, I'm not against the basic idea, it could work well for a car club where most vehicles are the same small type/size and easily towed/trailered.
Why not rename the board Transport Storage and Recovery?