A layman's questions about universes

It would make a lot more sense to you if you studied some tensor calculus and differential geometry.If you can't be bothered to do the homework needed to comment in an informed manner, you aren't going to be taken seriously.As it is, you're coming across like a witch doctor criticizing a cardiologist. That is, woefully uninformed about the subject you're discussing.

Nobody's insulting you. Your logic is self refuting, becuase it's not even addressing the problem at hand.Feeling insulted by being told you need to do your homework is not going to garner you much respect.

No. Actually, the mathematics fits right in with "common sense". We use the mathematics because it allows one to make clear, precise statements about the physics. As you are discovering, verbal analogies are insufficient.With relativity, one can make testable predictions of physical observations, that have in fact been verified. With string theory, the same is true. Certain elementary particles of certain mass should exist. Experimental tests of this are in the future, e.g. may need larger particle accelerators than current.It is getting difficult to escape the conclusion that you are slamming something simply because you don't understand it.

Like we keep telling you, you need more mathematics to truly understand how space is defined. If we tell you that in relativity, space is a 4 dimensional Riemann manifold with the Minkowski metric tensor, and where coordinates transform according to the Lorentz equation,and then go on to show, mathematically, how this connects to gravity...well, this is all graduate level mathematical physics.
There's probably someone on the boards who does this for a living. I just had the one graduate course in relativity, so I'm not an expert.It's not just mathemaitcs without physics, however. We can make testable predictions that have been observed. The precession of the perihelion of the planet Mercury was explained by relativity.
If relativity is true, starlight should be bent by gravity, and light should be redshifted when leaving a gravitational source. Both have been observed many times.And thats just for starters, in the string theory there are more dimensions...Intuition and "common sense" just don't cut it. It is what it is.Brian Greene (who does string theory for a living) has some books out on string theory for the popular reader. I highly recommend them e.g. "The Elegant Universe".