Is there a way to test my iPhone for any potential rogue apps
Apple is generally pretty decent with reviewing applications - HOWEVER - if you need to an application such as  http://www.digidna.net/products/diskaid   may help a great deal.

Truth to be told - the iphone is not secure period.   Just attend one blackhat event and keep your iphone bluetooth and/or wifi enabled and voila - folks can show you why 

Nicolas Seriot, from the Swiss University of Applied Sciences, has found some alarming design flaws in the iPhone operating system that allow rogue apps to access sensitive information on your phone.   (click on that last sentence for the link.