The merging and control of the fossil fuel industry under the Russian state is actually the opposite of what happens in the neoliberal hyper-capitalist nations that engage in imperialism today. Russia’s state control over its finance system is a reason why it is able to prevent the kind of hyper-financialization that has devastated Western industrial economies. China does the same but to a much greater extent since it is a socialist state.

Saudi Arabia does the same… Do they participate in imperialism?

Russia has no territory in Moldova. Transnistria is a de facto independent republic. The idea that Russia extracts some great benefit from this impoverished strip of land that is essentially blockaded by NATO vassal states is absurd.

In 2004, Transnistria had debts of US$1.2 billion (two-thirds are with Russia) that was per capita about six times higher than in Moldova (without Transnistria).[139] In March 2007 the debt to Gazprom for the acquisition of natural gas increased to US$1.3 billion. On 22 March 2007 Gazprom sold Transnistria’s gas debt to the Russian businessman Alisher Usmanov, who controls Moldova Steel Works, the largest enterprise in Transnistria.

You are stuck in a paradigm of imperialism that does not correspond to how imperialism really functions today, via finance and neo-colonial unequal exchange.

I think your definition of imperialism is necessarily pedantic to fit your argument.

There is only one imperialist nexus in the world now and it is centered around US unipolar global domination and their neoliberal hegemony.

And what theory on imperialism supports this claim?