Following a suggestion by Ratz, it is extremely easy in Life Balance to check for projects with no next actions.
(If what I write below does not make sense, come back to it after you have tried the software.)
What he suggests is to assign to each project name in the outline the Place of "Projects", which is set to be always closed. Then the next actions that fall below this are assigned to the actual contexts they belong to. So any project whose next actions are missing or are completed will show up in the To Do List in the place Projects, but only if you check the box for "All" instead of "Open" (this is so you don't have to see them if you use "All Places" to see all your next actions in one big list. If this doesn't matter to you, then set the hours however you like).
The point of this is that if you assign the place of "Projects" to all your projects, each of their children tasks will also be assigned to Projects automatically, and so any that do not have a next action will show up in the ToDo list when you invoke the place "Projects" . Then you can jump directly to the project in the outline and assign it a new NA if you want to, or check it off if it's done. And any projects that you do NOT see in the ToDo List have next actions assigned.
One more great feature that I can't resist sharing with you. Suppose you create an elaborate project with many subdivisions (children) at many levels, next actions, etc, and you decide you can't work on it this week. Just drag the highest level item in the project under a heading called (say) Maybe Next Week, and set that heading's importance slider to zero. The result is that nothing from that project will show up in your To Do List, but when you are ready to make it active again, all you need to do is drag it out of Maybe Next Week and back to wherever you want to have it. No need to redo all the planning work you already did. This works because LB does not put any items or subitems in the ToDo List if the importance slider is set to zero.
I am a Mac (and a Palm) user, so I don't know much about MLO or the Outlook Add-in, but for my money Life Balance is superb for GTD.