Not sure if this is already a feature. If the sim card is the known original sim card, optionally, can out-going calls be disabled on it, even if it is subsequently switched to another phone? (this stops a large bill being put on that account). If the sim card has already been changed, one might want to keep calls enabled just so that sms's can be sent. Alternatively enabling/disabling could be automatic as required.
Also on the subject of taking photos, there's not much difference between that and a shop owner having cctv, and photos might provide good evidence. If the owner instructed the phone to take photos, wouldn't that be a decision of the owner, not Avast, and so Avast could disclaim any liability? That's one for the lawyers!