- You can use URLLoader or Loader for loading the image if you are planning to cache the image on the client side, if you cache the image, it wil help you not load the image again when the users scrolls through the list. (What you have done is Ok, but you will hit performance issues)
- For variable row height, if Datagroup does not work, use List. find it here Flex 4: Setting Spark List height to its content height
- There should be a buttonMode property for some items, make it buttonMode for the logo, for variable row height, find something related to wordWrap and variableRowHeight properties on the datagroup.
There are a few suggestions, what you have coded is good, but, instead of adding the listeners on set data, add it in creation complete, as it is more appropriate. Also, the event listeners has to be weak referenced, http://help.adobe.com/en_US/FlashPlatform/reference/actionscript/3/flash/events/EventDispatcher.html#addEventListener()