Almost anything is 'possible'... now 'probable on a practical basis' is another matter...

These UAVs are not complete 'autonomous robots' - they are given commands like 'go in this direction' go at this height' 'go at this speed' 'go to this point' 'orbit this point' by a human operator.

The operator also depends on the on-board camera feeding back visuals thru satellites (which why the panic over China proving that they can destroy satellites in orbit!), and can then send commands such as 'lock target on this point' - 'launch weapon to targeted point', etc.

The cost of these beasties is such that the whole idea of using them as 'flying bombs' is ridiculous - there are much cheaper weapons - when you something that can hang around for 40 hours, there's far too many more useful things you can do, specially 'watch'... 'mere observation of the enemy' is perhaps the single MOST useful thing!

Now as far as using 'commercial airliners' as weapons - consider that the very people paying (bribing?!!) the pollies also want to make profits from flying these things around - while they MAY get some money from 'insurance' - they also own shares in the insurance companies, and too many 'losses' (don't forget the 'personal policies' payouts) will up the premiums on the planes and lower the insurance companies profits too...