Why is my questionnaire exploitable?

The problem with having old users review new user's comments is:

1. We haven't verified that they'd be willing to do this.
2. If a lot of new users come in all at once, that would be a chore.

This might actually scare off old users. Or create a backlog of comments to go through that prevents new users from participating. There's a high risk of this going totally dysfunctional. Unless you see something about it that I don't?