[kennybastani]

1. Adding nodes and relationships in Neo4j does not have to be slow. It really depends on how you are loading that data in. Neo4j provides many options for data import and a transactional endpoint over HTTP for batching transactions and decreasing disk write overhead.

2. The reason Neo4j is the only database that allows you to query a path is the same reason that setting up clustering or sharding is difficult. If your graph is complex then the problem is "How do I split up these subgraphs into shards so that traversals don't have to traverse across shards?" -- Building a giant adjacency list and using that as a traversal index is a clever idea, I must admit. :)