Disable HUD (Enemy Front)

Remove HUD

Go to the folder: \Enemy Front\Game2\
Make a backup of the file Scripts.pak
Open the file Scripts.pak using 7zip or WinRar
Find the folder HUD
Remove it.

Removal of the sight

Go to the folder: \Enemy Front\
Open the file system.cfg with Notepad
Find line g_show_crosshair=1
Change the value 1 to 0

The marking of the objectives of the mission.

Actually for this and created a topic: since the above methods waypoint is not removed, you can try to do it with trainers or replacing textures on transparent, here they are: