Encryption, you're into CAM slots and softCAMs, I think.
Porting to other systems, only if you have identical tuners - on that version, at least, all the records are keyed on the tuner name and the dvb adapter number, so these would have to be the same. Config files are in /home/hts/.hts/tvheadend if you want to dig deeper... easiest way is to try it and see what breaks!