I think you hit some hot topics for where I also hope this mechanism goes.

1. More scrapers
2. Some sort of rotation system based on some variables like location, OS, hardware, etc.
3. Transparency and verified identification of scraper operators, so perhaps eventually institutions/entities getting involved. A mix between individuals and entities I think would be best.

I think there are dozens of potentials with regards to where we can take this mechanism and I am very excited to see what people come up with. Things like the gamification/incentive potentials. Maybe second, third, or fourth sets of scraper nodes for collecting additional off-chain data/statistics from other distributed computing platforms (or other things like solar energy production) to be incentivized.

The round robin of 50 scrapers sounds a lot like combining Brod's DWP proposal with this scraper mechanism which I think holds potential, but would need input by more technically minded people.

For now I think keeping things as is is the most practical route as this scraper, while minimal, lets us focus on the other things we need to fix. I see this as a boot-strap of what can become a fairly intricate system that has some pretty neat effects. I would not feel comfortable with the mechanism as is if either the network grows rapidly or if a significant amount of time passes (for now, let's say a year) without revisiting its operation and the points you brought up.