I ran into the "Davison Hostility" bug, and instead of trying to run away and wait for 24 hours, I used the console, clicked him and entered the "stopcombat" (or thereabouts) command. This prevented me from getting the "Come Fly With Me" acheivement but all subsequent acheivements work just fine now.
So the other acheivements work just fine, but I'm wondering if the hardcoe acheivement works. Does it work by noticing you've had hardcoe mode on for as long as you've clocked gametime? Or does it work by simply noticing hardcoe mode is turned on at the time of the story-mode's completion? Will I still get the acheivement for it?
Cheers guys. Game on!