I think you are probably looking for something like this.
NOTE Quick Edit. Spotted an error. The property in the first node should be SequenceFile rather than SelectedFile, doh!
Its quick and dirty (but that's how I roll), I haven't tested it or closed references, but it is a good starting point for how to iterate through all of the SubSequences of a Sequence to get the Step Name and Unique ID of all steps in the Setup, Main and Cleanup groups.
Good luck!