Yeah, I'm not the one who said peaceful protests are the only way to do things. I disagree with that. Most effective protests are called violent even when they're not. The state will use violence against them and then claim they were violent. Peaceful protest can be a useful tool, but it isn't the only tool. Storming that capital building is not a useful tool though. It's only useful if you want to destroy a movement.

Coups however do often include physically storming buildings (or having access to it by default) to seize the legislature powers & using some sort of "official" pathway to power (just to have a basis for the administration & military to now follow the new regime as if technically nothing changed).

Sure, but it's rarely, if ever, control of the building itself that gives that power. If you can control the people who wield it and force them to grant you power, that's how it happens. That or kill them all and become the de facto controllers, but that requires a large military presence around the nation and that's what gives power. That's probably required in the case of any coup for that matter. Some people are going to turn against you and you have to be able to stop them.