On a raiding server, I don't want my players to store valuables at the player shops. It would be nice to be able to link a chestshop sign with a chest at another location so the chest would be at their house, vulnerable to being raided.

Not really easily possible in the plugin itself as it requires the sign right next to the chest as information about shops isn't stored anywhere else. I guess this could be implemented in a separate addon plugin using the provided events but seems a bit out of scope of the core plugin itself.