I'm with you so far, although it's still a pretty big leap, for me, to accept that Graendal realized the purpose of the emissary, immediately (or very quickly) after she became aware that Rand was about to weave Balefire. But the addition of knowing about the Balefire makes the idea less implausible, I agree.

I agree that there may have been enough time, but I just think it's unlikely she'd be able to do such a thing from a distance.

I like the way you included Aran'gar, though. I tried to think of a way for it to have been Aran'gar, not Graendal, who Compelled the emissary (and therefore that it was she who died in the balefire blast, not Graendal), but it just doesn't work. The Complusion was definitely done with saidar, since Nynaeve could see the weaves. That rules out Aran'gar's involvement, unless she and Graendal linked, and Aran'gar lead the link (would this be considered a 1man-1woman link, in which case Aran'gar would HAVE to lead?) and channeled saidar through Graendal. But that seems about as implausible as an idea can get!

If Graendal is still alive, it seems a reasonable conclusion, regardless how she managed to survive.