I'm a dummy with dos so I cant say if the command line works with firecracker software. Operating the modules while sitting at the computer is why the need for the interface.
(Since I'm paralized from neck down and keep a pc next to me all afternoon firecracker is quite handy)
Use of a third party sofware I cant say either. I can say they now offer software called Fuse that works with Firecracker that allows timed events (if this is what you mean by Third party software)and yes you would need to leave your PC on. They also now make a software addition for firecracker that allows creation of macros called MacroRecorder.
These 3 programs combined work like Activehome but without the need for the PC to be connect to an electrical outlet via the serial port cable(which connects to the PC module) and PC module(which plugs in the outlet).

As for the Activehome PC module interface, it has an internal timer but you must create the timed events on the PC then download those events to the PC interface then you may disconnect the PC from the interface.

Yes you can operate the modules with a palmpad totally independant of the PC as long as you have a RF transceiver. I hope this answered your questions. :)