In the data sheet it lists 2 contexts for a standard license on the FWSM "for testing purposes". What exactly does "for testing purposes" mean? Are these 2 contexts restricted in any way? Can I use them now in a prod environment and then upgrade the license later if the customer needs more?
With the basic/default FWSM license, you actually get a possibility to create 3 contexts (It include Admin context).
There are no restrictions. Infact the Admin context can also be used to do actual firewalling (i.e. like the other 2 contexts).