Forget Flat Earth Theory, now we have Flat Universe Theory!

[Anomalocaris]

If confuses me how anything that is infinite has a shape. So I'm just going to ignore this and go play in the mud.

No one knows if the universe is infinate in size or not. I personally doubt it, but I don't deny the possibility.
What the flat universe means is that you can't leave one spot, go in one particular direction, and eventually return to that same spot as you could on a planet like earth. It means that if you go in one direction for a long enough period of time, eventually you'll reach a point to where you can't move any further - depending on a number of factors.

The universe can not be infinite, it is expanding. Although for us in this small planet and an even smaller solar system, it appears to be infinite.

As far as being flat it makes sense. The galaxy is flat isn't it? The solar system is flat isn't it? In all probablity the universe is flat, and has to be if it started out in an explosion (big bang). Take a ball of dynomite, put a fuze, and light it up, watch the explosion and you will see that it will go out 4-5 times more than going up, basically it is flat. Put is a spin and it will be flatter.

I have no doubt that the universe is spinning just as planets spin around their sun, and solar systems spin within their galaxies, and galaxies spin within the universe.

You are mistaken in each of your assertions.

1. Something infinite can expand.

2. Most galaxies are visibly not flat but either spherical, ellipsoidal or irregular in shape. Only spiral and disk galaxies appears to be flat, but even in case of spiral galaxies the flatness is illusory. Vast majority of the mass of a spiral galaxy is also spherically distributed, the luminous flattish disk of stars in the middle is just a minor component of the galaxy's substance.

3. Solar system is not flat. The planetary orbits are flat. But the extended halo of cometary bodies in which the solar system is embedded is spherical. Even if it were not spherical to start with, gravitation perturbation by the planets and passing stars would randomize the orientation of the orbits in the cometary halo and make it spherical is an amount of time short compared to the age of the solar system.

4. The big bang is not like a dynamite explosion. It is an expansion of space, not an expansion of shrapnels through space. Space expands at essentially the same rate in every direction. This is easy to verify by a casual look at the temperature distribution of the cosmic background radiation, and can also be more elaborately verified using red-shifts and standard candles.

5. The concept of spinning universe is incompatible with the concept of 10^35 expansion of space in the aftermath of the big bang due to conservation of angular momentum.