Cool. I missed the secret ammo stash, but it was somewhat superfluous really! I also found it easier than seems to have been intended - the 'you survived against all odds' sentiment of the congrats terminal didn't really feel appropriate.
There are also a few inaccessible passages in the level, with drones behind pylons, but I guess they're just to add a bit of mystery and/or they were intended to be used in the level, but it was cut rather shorter than intended. That's how it feels.
As for EMR, waiting a bit is probably the way to go - I'll finish 2.1 and then go for the new 3 beta when it comes I guess, in the meantime.