All I was (constructively) suggesting was that we try to keep it focused on supporting the original poster; and his search for clarity.
There are (obviously) many devotee's of the GTD methods. Sometimes, people get SO devoted that they believe that what works for them individually is "THE Way" I drive to my favorite store one way. Someone else may drive another. Same outcome, different experience along the way. Once you start getting "locked in" to a rigid belief, then your openness to creative solutions gets suffocated. Not only that - but start "clinging" to that "one way" and feel as if you need to defend it.
There IS more than one road to Rome; and there ISN'T a clear cut "hyperlink" between Next Actions and Projects in the GTD systems. Part of that may be because the simplest level of GTD can be done with 3 x 5" Cards or scrap paper in folders. How do you "link" a project using those tools? Some people may even have only ONE Next Action list with less than 50 things on it. Do you NEED a link in a system like that ? It may be that you have a Project Schedule/Plan that exists on a separate piece of paper, while the rest of your data is digital - including the individual Next Actions that the paper "collects."
The other aspect that people are missing in this may be the NATURE of the projects that we all have. One type of "knowledge work project" may require a strong link; another type may NOT.
If I were to advise the original poster: I would paraphrase David re: Collection Buckets. - "Make it as complex as it needs to be (for your personal needs) - but NO MORE complex."