*What is on the other side of the disk
One thing that you need to know is that there are many different FE models. Many of them don't declare the earth is a disk shape.
In the more biblical FE models the other side of the earth is:
1. Hell
2. Sheol
3. The foundations of the heavens
4. The underworld
5. The foundation of the earth
6. Heaven
In the less biblical FE models
1. no one knows
2. The earth has no underneath because it is infinite
3. Space
*Is the disc rotating in any direction
Again when you use the word disk you are really eliminating many of the FE models in which the shape of the earth is unknown or where the earth is infinite.
Depending on the FE model you will get a yes, no, or unknown.
*How thick is the atmosphere (mol/dm3)
In most FE models this depends on the altitude. The atmosphere is less thick at higher altitudes and thicker at lower altitudes. This is not something that is readily discussed so i'm not sure about how the many models view this
*Is the atmosphere thickening or dissapering as we travel thru space.
In most FE models the answer is no. This is not something that is readily discussed so i'm not sure about how the many models view this
* I live in sweden and during the winter our days end at 3pm, how is this explained?
again this depends on the FE model. in a FE model with a tilting axis in which the earth orbits the sun the reason why is because your part of the earth is tilted away from the sun.
For the flat disk models the sun is rotating around the southern FE "hemisphere"