twychopen22 - a general principle I have learned, and you are still grapping with because you are still a beginner, is that you must work towards this idea... Your computer is an incredible resource that can do your work for you if only you can organize your thoughts well enough to tell it how to do so.
Part of the process of getting from here to there is to take Julius Caesar's approach: Divide and conquer. Break the problem down into components. If you find that you still don't understand a component, break it down some more. You must always shoot for the goal of breaking a problem into parts, each of which you can easily do without hesitation.
Part of the process of being good with computers is this type of analysis. As a case in point: Your idea that you could use a main form with tabbed subforms to assure that certain items retained their linkages is an example of breaking out parts of a problem. In this case, the part you were breaking out had to do with date issues on multiple parent-child relationships.
So whether this works eventually or you have to take yet another point of attack, it is the right idea conceptually to attack the problem this way.
Having said that, I regret I am limited in the amount of time I can spend on this because my local project work is getting hotter and heavier lately. I'll check back from time to time on several threads but I can only do limited coaching for a while.
