But to get to the real point here - why do you keep defending the actions of a blatant 19th century-style imperialist bully, as if it's some kind of calm, rational actor?
That's just, you know, doing what it needs to do?
Putin is a greedy son of a bitch. This is not a defense. It is an explanation.
In particular -- Russia most certainly does not "need" to dominate its neighbors. It's just what the current regime feels it needs to do to maintain its chances of survival.
Big difference, as you say.
Political figures and other individuals with their hands at the levers of power, on the other hand, do.
Specifically when they keep saying "Russia needs [to do various awful things]" when referring to the desires of the current regime.
In the case of Russia, it is completely appropriate to refer to the regime by country name, since Putin has been in power forever.
Anyway, this is a useless tangent. It should by now be clear to you and anyone else reading what I mean, even if it was not initially clear.
So no, Russia doesn't need the Crimea's resources either. It is however definitely very hurtful to Ukraine to not have access to those resources -- which speaks more to the true intent behind the annexation move.
It is necessary for Russia to invade ...
It isn't necessary for Russia to do anything at this point -- other than pick up its toys and go home.