The training burden for overland recoveries (not rescues) wouldn't be too great but that's for the accountants.
My point that the AA is operating Class One (JAR) in and out of helipads is relevant. When was the last time you practiced a rejected helipad? The safest place to go is back onto the helipad, yet the military don't have a laid down procedure for obstructed helipads. Some of the towering take-offs I've seen from helipads in congested areas would definitely result in an accident should an engine fail at the wrong time. This is considered an acceptable risk and everything is done to minimise that risk, yet if the military would take a little from their commercial colleagues the situation could be different.
Before I left, I had a go at a Class 1 helipad in the Sea King. It works and those that I showed couldn't believe that we weren't doing it.
Our rules for flight over land at night are 1000' above terrain/obstacles within 20 miles of track. Different over high ground of course.