I need to develop a touch screen app and wanted to know whether the standard events like button click , combo box select and others work in a touch screen when the same application that runs in a browser is ported to a touch screen , or do I need to capture the touch events separately .
You can use the same event, whatever trigger from mouse. Instead of mouse you r using Fingers or Pen. Thats it
Also, we've added an interactionMode style to UIComponent in Flex Hero. If you set it to InteractionMode.TOUCH, then you'll get a better user experience when using Lists or performing scrolling.
Flash Player will still fire equivalent mouse events along with touch/gesture events.
The "List, Scroller, and Touch" spec of the Hero SDK might be a useful read for you:
(specifically the "Mouse vs Touch Events" section)