I am no great fan of the EU, but the EU as a whole does not engage in much imperialism, besides that forced on it by the US.
This definitely looks like low-key imperialism, because the EU does not really have a reason to pay for an absurdly expensive Chinese-built highway in Montenegro, other than limiting influence of a competing power in that territory.
The Western Balkans and Turkey are the EU's immediate neighbors. Does the EU seek influence over what happens in such neighbors? No doubt. Does that count as imperialism? Not so clearly.
Russia is a major power, with the potential to be a major energy and military threat to the EU. Does the EU seek to drive the outcome of interactions with Russia? No doubt. Does that count as imperialism? No.