SureAI

OK. This area has caused a great deal of confusion. Firstly, I had the problem many people had thinking that I couldn't go outside at all because I needed my stuff first, but then through reading topics on the forum, I discovered you have to go outside to get the key to the door to get to my stuff. I've collected it now, but now I can't get out of the building. I found a key on a plate, but for some reason that doesn't unlock the door, and there doesn't seem to be any way to get out the way Kim got in. How do I get out?

Ok, as I understand you have found the second key and collected your equipment.
Now, have you found the secret passage in the very same room you had your equipment? Have you removed the crates using 'z'?
http://nehrim.wikia.com/wiki/The_Path_of_the_Gifted (slideshow : photo 14) or check the map for the location of the secret passage.
As far as I remember, it was possible to open only the locked door behind the secret passage to leave the Fort.
Good luck !