I'm guessing that you mean, "can humanity end". Yes. A major volcanic eruption can cause world wide temperature change and disrupt everything that sustains us. Whether it would end humanity depends on the magnitude and recovery time.
Don't worry, when it nappens you will experience it from the other side.
Yes it can anytime
It will, but not for a couple thousand years at least. Civilization will collapse much sooner though.
It will eventually when the sun expands