I don't believe Russia wants to control Ukraine long-term, nor do I think they're particularly interested in "regime change", though I suspect they would like to see whatever regime is in power rein in the extremist ethno-nationalist element that's creating a great deal of the chaos.
I don't see where Russia is interested in keeping the so-called "Ukrainian" people from either developing an identity or having relations with other nations, though I'm sure they [and this would be true of any nation] wish to protect their interests there. Their opposition to the EU trade agreement that Yanukovych didn't want to go along with unless it included significantly more capital investment wasn't so much about keeping Ukraine from doing business with the EU, but about trying to bring about a "tripartite" agreement that would have benefited everyone. The EU, being the EU, basically told Yanukovych that he could either do business with them or with Russia, not both. Of course Russia, which already had trade agreements with Ukraine, objected to that, as did Yanukovych. So, naturally, he put on the brakes.