I just bought the Pro 2 years for the price of 1 deal and somewhere during the purchasing process it said that the license period start date was the date of purchase, not the date of activation. Based on that, I wouldn’t buy a license now hoping to use it at a later date.
EDIT: You’ll only be missing the sandbox and Script Shield if you downgrade to Free. I’ll most likely stick with Sandoxie and only upgraded to help support the devs. I’m not sure that Script Shield is going to make much of a difference. I can’t seem to find any good information on exactly what that shield does in addition to the File Shield which AFAIK scans scripts too.
Tell me about it! I had to manually open a new tab and search Google to find out what Finjan SecureBrowsing was all about. It would have been a lot easier if you had a link to take me straight to their homepage! LOL! ;D