Ges:
I think your theory needs to be reformulated in terms of mathematical expressions, and clear, refutable claims, otherwise you won't convince anyone. I reccomend you read Kuhn and Popper, or at least a good summary of their work, which can be found at:
http://www.humanists.net/pdhutcheon/Papers%20and%20Presentations/Popper%20and%20Kuhn%20on%20the%20Evolution%20of%20Science.htm
Also, I'd like to see a citation for your evidence that the earth and other planets are expanding. I am somewhat familiar with this conjecture, but at a perusal, it doesn't appear to conserve energy, or provide an explaination for destructive plate boundaries. A big part of your theory relies on an unprovable premise.
Even if we accept your theory as true, that planets expand causing a greater inward 'vaccuum force', it does not explain why all objects with mass do not similarly expand. What is special about the earth? Laser interferometry could easily detect such minute expansions.
In your post, you say that space is a vaccuum while earth is a collection of matter. If the only force holding the earth together is gravity, and you state that gravity results from your reverse vaccuum theory, then why wouldn't the earth immediately disassociate? It would be exactly like free expansion of gas. We would observe at least the atmosphere of the earth quickly drifting away, followed by the boiling away of our oceans. Yet, we do not observe this.
There isn't a law of thermodynamics that provides the condition for the sort of on/off vaccuum your theory requires. Your theory does not explain how planet formation occurs in the first place.
Why do objects moving at relativistic speeds have greater mass, and a greater observable gravitational field? Shouldn't motion have nothing to do with a vaccuum? How does your theory predict gravitational lensing? Does your theory allow for the precession of mercury around the sun due to General Relativity?
What new phenomena does your theory predict? Why is it better than the theory of gravitation?
I'm new to this forum, and I see this thread is posted under the pseudoscience heading. The pseudo science heading seems to suggest that this part of the forum is a place where the rules of good science no longer apply. If this is true, than I am sorry to bother everyone. However, it sounds like you're trying to convince people that your theory is correct, so I see no reason why we shouldn't apply the scientific method.