I am running with the Wasteland Wanderers mod
About the landmine death, I have not had a chance to find out why I can't disarm them. My best guess is that the mod I am running aims to make the game more realistic and as such my explosive skill is probably too low to disarm them.
The Outcasts in Fort Independence will pay you for hi-tech weaponry and parts. They pay in ammo and aid rather than caps. If you don't plan on using energy weapons they are a good option for offloading your stuff.
Fairfax Ruins is a fairly tough Raider location. I started to explore the underground tunnels but when I start to get low on food and water I run the risk of becoming severely impaired. As such I thought it best to get back to Megaton before I found myself unable to fast travel.
When playing with the Wasteland Wanderers mod it is important to understand how it impacts your gameplay. While you can set the game to be harder (or easier) I prefer to go in the more difficult direction. When playing under the vanilla rules you can quickly become god-like and acquire an overabundance of caps. With this mod ANY encounter can do you in.