Russian Missile hits Turkish ship...

[nzoomed]

Not only the end of Russia, also large parts of America and nuclear fall-out on a large scale which will affect the weather and plenty of other parts of our lives.

Times not right yet for Putin to use nukes, depends on the outcome of the war, if he loses then nukes will be used unless he is assassinated first.

I think its more likely that either Putin gets overthrown or is assassinated as you say before Ukraine even has a chance to win the war, that would be the best outcome, but even better if the whole Putin regime gets overthrown with a more democratic Russia. The concern is that someone will simply replace Putin with similar views as his.