Daily trading exchanges limit will be set while you create your MultiToken. You can choose between two options - certain percent of token price or fixed amount depending on the type of rebalancing chosen. All the exchanges done through this MultiToken will lie in those limits. MultiTokens which will include MTK tokens will be involved in the exchanges more often than without it. This feature is still to be determined and some details much change in the future.
exchange and arbitration are different things? how should it work?