Get crosshairs into FPSC is tricky? My goodness it's about the easiest thing to do. But as long as AE gets people to believe it's hard they will keep on buying his pack.
Here's how to do it:
First of all create your crosshair. Preferable, create a 64x64 image with a black (RGB 0,0,0) background. It must be black. Now create your crosshair on top of this. Once done, save the file as a 32bit .TGA file (TrueVision Targa Format) in the folder where you gun is located. The filename NEEDS to be crosshair.tga
All guns are located in the files/gamecore/guns folder. In that folder locate the gun which crosshair you want to change either your own created gun or an exsisting gun. Let's assume we're going to change the Scifi Vickers Gun it's crosshair.
In the files/gamecore/guns folder select the scifi folder and then the vickers folder and save the file crosshair.tga in that folder. You will notice a file called crosshair.dds in it also. Before you run FPSC, rename that file to something like original_crosshair.dds This MUST be done, because the engine uses the crosshair.dds in the game. Now run FPSC, pick the Vickers gun and voila a new crosshair will appear. If you go back to the vickers gun folder, you will notice the engine has created a new crosshair.dds file.
So in short, create a 64x64 image and save it as crosshair.tga in the gun folder. Locate the gun, all guns are (and custom guns must be) in a subfolder of the files/gamecore/guns folder. Now rename or delete the crosshair.dds file.
That's it. Imo making crosshairs is about the easiest things in FPSC.
Have fun doing it!