RE:$$ ; Well, first off, whether Russia declares it or not, everyone acknowledges that this is an all out war. I don't think that there is a single significant city that hasn't been attacked.
Putin might think he could disrupt development of the Bulgarian gas fields with no significant political blowback. That might be the case, but Europe has to either show support for Bulgaria, or accept that Russia dangles the Sword of Damacles over the entire continent.
On the SASB Gas field, Putin dare not interfere. It's 51% owned by the Turkish government and any interference there would result in Turkey closing the Dardanelles to Russian marine traffic which would be catastrophic for Russia.
The shift away from Russian based energy is long term. How long has Iran been out in the cold for far less serious infractions? The real question is how do the other energy powerhouses like Kazakhstan line up?