Hello.
Please kindly read my comments on your requirements. I've done similar things in the past, but we need to tune your specifications a little bit.
About #1.
By "From a CSV file ... a random number of sequential files ..."
I think you meant "sequential PHONE NUMBERS". Am I right?
About #5.
Is the "file hosted on a desktop" static? Will it be modified at some time? If yes, could that happen in the middle of the SMS sending session? I'm asking this because in such case, a simple resume (from where it left off) operation may not be suitable and we could need a more advanced method, like using a database.
About #6.
Should I understand that the message text can be variable accross sessions?
About #7.
AFAIK, there's no way to automate that by USB unless we have some custom app listening at the other side. The method to use in this case is treating the attached phone as if it was an USB modem. We may need to do some tests with your devices to be sure this approach will work with no problems.
About #11.
I wonder why would an "average high school graduate" need to send hundreds of thousands of messages.
I am not sure but maybe there are limits imposed by the mobile provider? Even an unlimited plan has limits (kinda undisclosed). They are usually high, but we'll be dealing with huge numbers here.
That's all for now. Looking forward for your reply.
Sincerely,
-DEN!