He has in fact died. This is not going to end well
I don't see any major difference. The perp was likely a member of one of the groups already fighting Russia in Syria. So Russia will likely just bomb Syria more. That sucks for Syrians, but I don't think changes much.
I doubt this will change much in the relationship between Russia and Turkey. Erdogan will likely use it as an excuse to crackdown even more on civil liberties, but I think that was coming regardless.