One thing you should remember is that graphs are relational structures. The fancy thing of neo4j is not that it stores graphs (any relational DB can store graph

One thing you should remember is that graphs are relational structures. The fancy thing of neo4j is not that it stores graphs (any relational DB can store graphs) but it stores JSON-(like)-Documents and it excels at algorithms for huge graphs (million of nodes and beyond). I doubt that your users will manage such large mind maps. Therefore, use a traditional DB system and write a GUI to solve (a). Neo4j's admin console isn't meant as a front end the same way Djangos admin GUI is not.