They killed him after several hours of negotiation. I would assume that several hours was enough time to get any civilians out of the line of fire.
We don’t know. A 6th(?) floor parking garage could have a very extensive field of fire including nearby buildings.
Waiting for dehydration to impair the suspect would be very difficult in that case.
But the point is that the danger to the public is the central factor to be considered.
It’s interesting to consider this in terms of Posse Comitatus theory too.
If a bomb ‘IS’ needed is it better overall for Posse Comitatus to be suspended or weakened so the bomb can be delivered by a military force instead of the police?