My pleasure, and feel free to hit me directly if you'd like feedback as revisions are implemented. As for the character limit, 300 is much more appropriate I think. It's a catch 22 in a way - journalists/bloggers theoretically want a lower limit with the hope that they will receive a succinct message. Businesses/flacks on the other hand, will be put off if they have to keep revising their thoughts over and over to fit them into such a small space.

Personally, I might start with a limit of 500 characters but I'm likely in the minority. For comparison sake, this message is 593 characters.