[trevelyan]

> However depending on the architecture that is the only motivation needed and depriving others of rewards; in the long term this could result in centralization of routing nodes (by control) and finally censorship.

Highly recommend reading the original paper (!!) as the "depriving others of reward" concern you have is exactly what is solved through sybil-proofing. So the solution addresses your concern directly -- nodes share because it is profitable for them to do so, and it is profitable for them to do so because others cannot deprive them of their due reward without losing money. If we are both nodes then I'll give you my TX flow because the only way it has value to you is if you figure out a way to get it confirmed faster than I can.

> how does the entire network agree on the minimal routing when there are many routes with the same 'depth'

A good technical analogy is to think about how POW works, but have users attach a difficulty-hash to their TXS instead of a fee. Have nodes "collect" those hashes to meet aggregate difficulty requirements. And now have consensus halve the "measured value" of the tx-embedded hash for each hop in its routing path. Early-hop nodes in this system will have a similar statistical advantage producing blocks.

The POW analogy suffers from attack vectors that are not possible in the sybil-proof mechanism, but it should give you a sense of what is happening. An attacker can create 1-hop routing work using their own money, but in that case they are making blocks with only their own wallets and pay the costs of hashing/burning to release payments entirely out of their own pockets.