Maybe an n^2 flag weight curve is not even the best solution

Something that comes immediately to mind is that this can also be abused. Maybe an n^2 flag weight curve abuse could be mitigated by an SP^2 cost in doing so. I don't think it's a good solution, but something along the lines that prevents abuse.

a system could be suggested that factors in the total number of votes, pageviews, etc.

I think this is probably the way to go. There's probably some allocation of upvoting and flagging based on SP that balances the power between smaller users and larger ones.