I believe that the government would try very hard to portray storming a prison today as a terrorist attack. Most governments are not in the business of giving up power, they are in the business of always acquiring more. Allowing citizens to storm a government facility would make them appear weak, which is not acceptable.
Of course the storming of the Bastille in the French Revolution would be considered a terrorist attack today, a domestic terrorist attack, but a terrorist attack. The mob demanded a violent overthrow of the existing government. The prison represented authority. The storming of the Bastille was an act of domestic terrorism by definition.
Yes, it certainly would. In our modern, security minded and overly paranoid version of the world, any movement against the government would be instantly labeled a terrorist attack. Of course, such a storming could never actually happen today, not with modern weaponry costing hundreds of millions of dollars that civilians can't afford to use.
I believe most attacks in past wars would be considered an act of terrorism today. That is one of the problems the world is facing, in as far as dealing with terrorist. We have over used the terminology, after we set up special laws that only apply to terrorism. Frankly, it's a mess and I don't think we should consider everything terrorism, as we are trying to do.
No, the storming of the Bastille during the French Revolution would not be considered a terrorist attack today, because the storming of the Bastille was done for a valid military purpose. Those who attacked in Bastille were trying to change politics in their own country. They were not trying to convert people to their own religion with bloodshed.