To prevent abuse, GMs should be permission restricted (via GM level) to trade with other non GM players, use their storage (prevent transferring to their other characters), send via Duey and to drop items. GM level is configurable.

src/main/java/config/ServerConfig.java

@@ -309,6 +309,12 @@ public class ServerConfig {
     //Event End Timestamp
     public long EVENT_END_TIMESTAMP;
 
+    //GM Security Configuration
+    public int MINIMUM_GM_LEVEL_TO_TRADE;
+    public int MINIMUM_GM_LEVEL_TO_USE_STORAGE;
+    public int MINIMUM_GM_LEVEL_TO_USE_DUEY;
+    public int MINIMUM_GM_LEVEL_TO_DROP;
+
     //Custom NPC overrides. List of NPC IDs.
     public Map<String, String> NPCS_SCRIPTABLE = new HashMap<>();
 }