The Russians will be in a quandry.
1. if it was a bomb then they would be forced into some retaliatory action which they probably do not want to get involved in for all sorts or reasons.
2. If it was crew or technical failure then that is not much better as it was their crews and their airlines operating it.
So on balance the Russians would probably hope it is some undetected and undetectable technical issue with the aircraft or engines.
I donīt think so.
1. I think that Putinīs words that "any attempt to intimidate Russia will fail and they will continue to fight with terrorism in Syria and anywhere" are clear enough. Also increase of fight activity in Syria right after disaster is visible.
2. MetroJet probably will finish operaton soon because of Rosaviacia measures. The same as most of companies after fatal disaster in Russia. And donīt forget, Metrojet is Russian company only "de iure".