I feel for you.
NWP have a good interpretation of what is reasonable, and provided your behaviour is reasonable they're happy.
For example, let's presume I want to collect my rifle from the gunsmith after repairs, and my wife wants to go shopping. the supermarket is at the other end of town from the gunsmith, so she drops me off there as we pass, and I arrange to meet up with her later in the supermarket car park. So, I collect my rifle, in a slip of course, and walk through town to get to the supermarket. On the way I go into a couple of other shops and the bank, with my rifle. That is reasonable behaviour and wouldn't raise any eyebrows. However, if I'm still walking around town with a rifle 4 hours after collecting it then that wouldn't be reasonable.
Likewise, shooting from a public road that happens to pass through my land (unfenced), no probs provided all is safe and no-one endangered.
Crossing roads from one piece of land to another - no need to cover rifle, as perfectly good reason for being there.
etc etc.