Don't worry about the update for the moment. The next Part of Module 1 will have it included anyway.
The white horizon is due to your graphics settings. Looks like you are not in "Perfect Mode"
Most mod maps should only be run in Perfect Mode.
Your sea details appear pretty bland too. Similar problem.
Not a CUP issue, just a general game optimisation issue.
Best fixed by editing conf.ini --- read here
https://www.sas1946.com/main/index.php?topic=9756.0 Make a backup of conf.ini before editing it. Spend some time experimenting to get things looking sweet.
The best settings will depend on your system.
Assuming you are using OpenGl then concentrate on this section of the conf.ini. The following are from my install (only for nVidia type graphics cards).
//[Render_OpenGL] //for NVIDIA
[Render_OpenGL]
TexQual=3
TexMipFilter=3
TexCompress=0
TexFlags.UseDither=0
TexFlags.UseAlpha=0
TexFlags.UseIndex=0
TexFlags.PolygonStipple=1
TexFlags.UseClampedSprites=0
TexFlags.DrawLandByTriangles=0
TexFlags.UseVertexArrays=1
TexFlags.DisableAPIExtensions=0
TexFlags.ARBMultitextureExt=1
TexFlags.TexEnvCombineExt=1
TexFlags.SecondaryColorExt=1
TexFlags.VertexArrayExt=1
TexFlags.ClipHintExt=1
TexFlags.UsePaletteExt=1
TexFlags.TexAnisotropicExt=1
TexFlags.TexCompressARBExt=0
TexFlags.TexEnvCombine4NV=1
TexFlags.TexEnvCombineDot3=1
TexFlags.DepthClampNV=1
TexFlags.SeparateSpecular=1
TexFlags.TextureShaderNV=1
HardwareShaders=1
FogLow=1
FogHaze=4
Shadows=2
Specular=2
SpecularLight=2
DiffuseLight=2
DynamicalLights=1
MeshDetail=2
VisibilityDistance=3
Sky=2
Forest=3
LandShading=3
LandDetails=2
LandGeom=3
TexLarge=1
TexLandQual=3
TexLandLarge=1
VideoSetupId=17
Water=4
Effects=2
ForceShaders1x=0
PolygonOffsetFactor=-0.0625
PolygonOffsetUnits=-1.0
For some basic advice try reading here
http://www.gog.com/forum/il_2_sturmovik_1946/make_il2_pretty_guide