We have the capability to fold the Flash Builder perspective into the My Eclipse For Spring IDE.
Modifications can be made to the Flash Builder mxml. When you execute the MES as a Tomcat application you will notice the changes are not reflected. That is because you first have to re build the application to pick up those changes. To accomplish a successful update go to the build folder associated with your project open it up. Build each entry in the folder. Simply right click on each item and select the Ant Build option. Now run the MES
Other tips would be to make the date data type in MySQL activates the flex date picker control. To make the flex memo feature operate use the text data type in MySQL.
To change the overall look and feel of your MES generated application you want to create a customization project. The link below describes how to create such a project.