When creating a text blast the character count should note that the count includes spaces.
Thanks for pointing out that detail for us. We included a line about what is considered to be a character in our documentation: http://nationbuilder.com/text_messages#send.
Totally. For now when you are IN your control panel the number of available characters goes down as you add spaces.
But we can definitely update the documentation to reflect this as well. I will let you know when it's completed.