System in Off mode, a smoke detector activated, then the system switched to Away. -- normal ?

No, not normal - a change to Away mode after being in OFF should only have been due to you putting it in Away mode - if you or no one else in the house did that, it's not working properly - call SS for troubleshooting (try calling first thing when they open, 9am ET, and pressing #1 for sales, hopefully someone will answer sooner).