Quote: "will the numbers at the top of the screen be eliminated?"
The numbers on the top are just the lives and health numerics, you will be instructed to just delete those from the setuplevel.fpi
Quote: "If you pick up the gun, will the pic in the HUD change?"
yes, the ammo image that is used by each individual weapon will show there,it will be the users responsibility to scale the hud_icon.dds used by each weapon to fit within the HUD.
I have added a blank.dds file that will force these images to automatically scale to the correct value but may make the image distorted so I do recommend scaling them within a image editor.