1. They likely won't occupy all of Ukraine, but I doubt it was their initial goal.
They may still occupy all of the eastern part. In any case, it's pretty unlikely they will just pack and go home.
3. Not every person, there is some redundancy in the chain exactly to make sure it will work even in case of a few people who wouldn't press the button.
>> Russia is restoring its unity - the tragedy of 1991, this terrible catastrophe of our history, its unnatural dislocation, have been overcome. Yes, at a high price, yes, through the tragic events of the virtual civil war, because now brothers separated by belonging to the Russian and Ukrainian armies are still shooting at each other - but Ukraine will no longer be anti-Russia. Russia is restoring its historical fullness by gathering the Russian world, the Russian people together - in its entirety of Great Russians, Belarusians and Little Russians. If we had abandoned this, allowed temporary division to gain a foothold for centuries, we would not only betray the memory of our ancestors, but would also be cursed by our descendants - for allowing the collapse of the Russian land.
For reference 1991 is when Ukraine gained its independence.