The projects are separate for historical reasons, I think it’s time to merge the three projects into one. I think it would ease searching for a bug, and following the development process as a whole.
You were right, and I think having one issue tracker goes to that direction.
My favourite view of the project is current status, which does not show what happens on NethForge and Nethgui. Maybe what I need is only a Redmine query that shows all the projects together, that can be easily accomplished by moving NethForge and Nethgui as subprojects of NethServer.