Zero chance any of that would have happened. It certainly could have gotten more ugly than it was. But a loosely organized mob of protestors is not going to achieve that. One SWAT team, or the military if necessary, would have dealt with it easily.
Zero chance bull. The majority of the mob were not organized, but there was a core of co-operating individuals that came prepared with Kevlar, weapons, specialized restraint zip ties, etc, and appeared trained. Who knows what would have happened if they had breached sooner than the Senators/Congressman could have escaped to safety? And without that branch being able to function, who knows what Trump might try to claim empowered to do?
Is this likely? Maybe, maybe not. But I tell you what. There is more danger to under-emphasizing the threat than over-emphasizing the threat. Indeed, fear and control over executive power is at the core of our Constitution and founders' fears. I will not play down what happened, and who instigated it.
The general mob could also have quickly instigated a massacre. Chants of "Hang M. Pence."
Over-emphasizing the threat could have taken the form of five times as many police in riot gear surrounding the Capitol. That would have been fine (hopefully). Or it could have taken the form of police deciding to open fire, which could have killed a large number of people and had enormous and unpredictable political consequences.
Over-emphasize isn't enough. It has to lead to the right actions rather than to damaging ones.