I have never caught the significance of why the wild wasteland eerie music plays at the Old Fort Mormon. What am I missing?

Also curious about the "soon to be attacked" music at the Mojave Outpost. There are never any enemies near, even with ED-E's sensor range.

I have no idea about the Fort, but the area to the NW of the Mojave Outpost is all surrounded by Scorpions and Ferals. ED-E is picking up scorpions most likely.

Also there is a cave that has about 7 Night Stalkers outside next to the big long road up to the Outpost.

There are several Wild Wasteland encounters in Freeside. I think they have to do with what people in Freeside say under certain conditions. You need to have Cass with you for one of them, I think, and you need to be Vilified for another. There's also an encounter near Cerulean Robotics where you get attacked.

Radscorpions from Mesquite Mountains Campground sometimes drift close to the Mojave outpost.