I am glad the note helped, and prevented the disaster. I think the note was too vague, why not add just the name to it, like write "Aschen" down too?
The note worked but they got lucky, lucky lucky. I mean finding the underground city under the farm, calling their bluff and avoiding the bioweapon? It was too close, but that makes for a good story. Still, if you are going to send a note back from the future, it should try to cover all the bases, they are altering the timeline anyways by doing that, might as well try to alter it in the way they intend rather than leaving the note open to debate and chance.
One other thing is I think they should have mentioned the 'sterility' thing in front of McKinsey and the President, that way they would have much more to go on than their word. The 'translation' final scene was awesome.
I actually saw this episode before I saw the first one, "2012", and it is much better seeing the first one.
The best foreshadowing was this:
"You'll find we are a very patient people, Ambassador."
Very patient indeed