While there's a gray area where there can be disagreement as to whether it is sufficient justification, after a certain point, pragmatism must prevail. Using the 2nd amendment as example, lets say we allow guns and rifles. And grenades? RPGs? Tanks? Chemical weapons (nerve gas, not pepper spray)? Biological weapons (smallpox, not guard dogs)? The only thing that can stop a bad guy with a bioengineered plague, is a good guy with a bioengineered plague?

It should always be ignored. If the states want to ban people from having tanks and jet fighters, they can adopt a new amendment. There's already a process to account for these types of things.

Yes. Maybe not simply video but what about a deep-fake video designed to deceive people that is indistinguishable from a genuine video? At some point unique cases arise that require careful judgement. This is what the judicial system is for, to provide "judgement" on things which were not anticipated by the law.

Sometimes those unique cases were only once unique but become ubiquitous due to changes in technology, geography, climate, or society.

right to privacy is an example. There's talk about this all over the place but it was only evident that people had an expectation and desire to exercise this right after it started getting abused by technology and technology companies.

The bill of rights contains what it does because the founders had just had experience with many of those rights being curtailed.