It should some some positive and negative trust like what we have in bitcointalk.org so that people might know that those helpers are legit and not selling their reviews,so that the system wont be that easy to crack,because these greedy people will always find there way to make money.
You may have a point on this one mate, but I think those people that who are greed will no longer be disappear in any form of business, especially in this type of business isn't right? So the better way for us to avoid this things is we must be careful in everything we choose to be involve in any project like this one.
I think this is possible, we really are waiting to see what Lina.review platform will look like and how will it function. I hope I can participate in the testing of Lina.review.