If I understand correctly it is also illegal to conduct trade in Russia between a Russian individual and / or legal entity and another Russian individual and / or legal entity in USD, EUR etc., so in effect this places Bitcoin in a similar position to that of USD, EUR etc.
Correct, it is illegal to trade, transact or deal in foreign currencies in Russia - unless one party to such deal is a properly licensed financial entity. There are multiple bank exchange offices everywhere in Russia, so exchange between foreign currency and rubles is not a problem.
Situation is completely different for cryptocurrencies. Since Bank of Russia specifically prohibited financial entities from touching cryptocurrencies, any kind of Bitcoin use is now considered illegal for anyone. There was no statement on the legality of their ownership just yet.
As I understand this, trade with or use of bitcoins is illegal now, but not holding bitcoins. Otherwise it would be illegal to hold physical USD or EUR on Russian territory too.
And what law prevents a Russian to buy bitcoins on a foreign exchange and keep them in a wallet abroad?