How about this:

During Preparation Phase (50 hours), if the Rating went up everyone will be eligible for a slight discount on Cluster, Peacock Ore and Coke in that specific Hamlet, until the end of the following Battle Phase (25 hours). Rating 1 gives 5% discount, Rating 2 gives 10% discount etc. In addition, expand the Hamlet trader content to include region exclusive item to give incentive for raising all Hamlet rating.

During Battle Phase (25 hours), if you succeed in defend the Hamlet once, you are eligible for bonus to Gathering for a specific class (Hyrstmill -> Botanist, LL Hamlet -> Fishing, Uldah Hamlet -> Mining). For example Rating 1 win will give you 2.5% bonus on Perception up to 3 limit and 5% extra EXP from gathering, rating 2 win give you 5% bonus on Perception up to 6 limit and 10% extra EXP from gathering. This buff last until the end of the next Preparation Phase (50 hours).