Are my conclusions correct in context of these examples of forceful extraction of money?
Well this is trivially true because GDP measures output. Here the only producer in the whole economy is the teacher, if the bandit or government can make teacher work more then of course GDP increases.

Note the GDP increase here because the teacher actually produces 200\$ worth of services not because money ‘circulate’. You can calculate GDP even for barter economy where there is no money. What matters is that this bandit or government managed to ‘convince’ the teacher to produce 200\$ of services.

Even in a totalitarian society where everyone is forced to do things at the end of the barrel of a gun GDP won’t be necessary zero.

However, this being said it is not realistic to assume that if government set taxes to 100% people will still provide goods and services assuming government can’t use forced labor.