Im wondering if you have considered this, I haven't seen it anywhere:

1) Allow NAT clients to be TOR relay nodes (even maybe exit nodes) , this would be done using a queue system, possibly in a hidden service but not necessary, where nat relay nodes can query what tor clients want to connect to them and initiate the connection. This would allow more nodes in the TOR network.

2) Reduce the bootstrap file size clients download. An increase in nodes would increase the file, roughly 1.5mb right now, this file could be decreased to 10k if clients would first download a list of hashes that identify each OR, then they choose randomly and retrieve from the directory the information for each of the hashes they choose. This would be a temporary way to start connections while the real bootstrap file is being downloaded. It would only benefit those clients with slow connections.

Thanks