This. Same thing I do in FO3 & Oblivion.
Edit: oh, yeah.... and loot everything not nailed down. Packrats ftw. :celebration:
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As for the one unkillable person.... honestly, I couldn't care less. I've actually never gone out of my way to kill lots of named NPCs in previous gamesas games. My FO3 exploits are typically restricted to small areas (like the Family, once or twice. And Paradise Falls, every game. Or the Republic of Dave, once.) But Megaton, Rivit City, the BoS, etc? Never tried killing them. No reason to. And, yeah - that means I've never actually had a neutral or evil playthrough. I just can't seem to manage it.