>is it good to create sections in the Data class and use the flow actions in the work class
You can only associate a section to a flow action with the same Applies to class, hence usually you need to define flowaction/section pair in the work class.
However for the shake of re-usability and the consistent display of same set of data across the multiple screens, usually the section defined in the work class includes those sections defined in the data classes.
It depends on how you use the flow action. There are design patterns for defining flow action in data class, however you can not refer data class flow actions in the flow rule of your work class (split for each shape is an exception).