I think it can it be easily cut using a bolt cutter but we shouldn't really concern that much, because when it involves a forcible break in, not much can be done..

i went to their show house in usj one avenue end of last year. the grill is still visible from outside(100-200m), but not visible from far away. price is around rm16 per sq ft, cheaper than normal iron grill (around rm18 per sq ft) if im not mistaken.
it can connect to alarm system cos the cable can conduct electricity (but its covered by an outer layer - so no harm to user). so, if the circuit breaks (the cable is being cut), it'll trigger the alarm. the cable is very strong, can hold around 200kg tension (around that figure la, cant remember).

Yes, it can open. I personally feel it look ugly from inside the house.  I prefer normal frill with Horizontal design.

If it use the high tension as alarm detection, is easy to bypass alarm, just short the both end of the high tension cable with longer copper then cut the center.. Done. 

If use shock sensor, is even easier, just hold the both end of the tension cable with plier and cut the wire in between. No shock will be detect.

Market is bad.. got to find more business