Mirroring is something I need to consider. You and Broiler did mirroring, which means you helped PUBLISHING so, I just can't miss that ;) (I'm the worst person at mirroring, bleh...)
Lol, well, I have to say that my maps aren't the easiest around. You should not cheat! That map is supposed to be hard! Save often... and, be reflexive ;) Trust me, you'll be perfect after playing over and over as you'll learn where they'll show up, and your shotgun will be ready to pump it's shells!
I can give you tips on how to beat some of the enemies, if your situation is so desperate, otherwise, find out yourself :)
Yeah there is... You get it after you kill the Overlord's at the arena at E1L3... and with the new update, you get it in a secret area at E1L4. You can check the thread for the new update ;)
Good that you replaced your hd. I hope you won't have any further problems with it.