There is a difference between "decentralize everything" and "this is probably not decentralized enough". Having a core mechanism that can be easily corrupted with minimal effort or cost is fairly dangerous. Look at EOS and other DPoS systems along with the words of incredibly reputable figures in the bitcoin and blockchain and how they approach decentralization.

This is a mechanism that should be as decentralized as possible. It does not need to be 100% distributed, however.

To be clear, though, 5 is fine for a boot-strap. It's similar to how bitcoin started.

Scrapers waiting in the wings is a good idea.