If you add the variable of the gas supplies found in Crimea, it makes even more sense.

He wants to keep control over Europe and that would have been an instant loss as soon as production went live.

I believe the takeover over Crimea was primarily for this. The rest was a result of what he thought "preparation" to cement commodities/gas within his influence.

He's a bit jealous of China too. Russia has all this territory and doesn't even remotely gets the respect he screams for, at least he isn't getting it from the west.

It's a tiny man with a big ego.