Yes, these are sound ideas, but such a system needs to undergo a number of balancing iterations.
As for the huge number of PRs, it's an arms race. The slew of generated PRs needs to be responded to with similar automated tools—and I'm not just talking about generation, but also about deterministic checks, and with them, raising the requirements for PR formatting.
Plus, you can create a funnel of checks—from new community members to more experienced ones—which will give them the opportunity to prove themselves and build their reputation.
As for the huge number of PRs, it's an arms race. The slew of generated PRs needs to be responded to with similar automated tools—and I'm not just talking about generation, but also about deterministic checks, and with them, raising the requirements for PR formatting.
Plus, you can create a funnel of checks—from new community members to more experienced ones—which will give them the opportunity to prove themselves and build their reputation.