Russia certainly doesn't have any legitimate sphere of influence for countries outside the former Soviet Union, but it does have legitimate rights to guarantee the freedom and safety of Russians living within the borders of the Soviet Union but not Russia. The Ukrainian "revolution" was accomplished with the help of violently anti-Russian elements who are now patrolling Kiev. Signs are put on buildings saying "Russians live here" so that the lawless elements running the capital can rob them. Members of the Rada are beaten in public if they are from the East. The pro-Nazi Right Sector, which has all the guns, has openly Nazi symbols and an openly National Socialist ideology. About 23 million people in the Ukraine (about half the population) speak Russian as their primary language, and about half of them are listed as ethnically Russian, and they are at risk.
Your notions of the strength of Russia are also flawed. Russia's economy is dependent on oil and gas, yes, but it is the eighth largest economy in the world (http://en.wikipedia.org/wiki/List_of_countries_by_GDP_%28nominal%29) and it is much, much wealthier than you seem to think.
Also, Russia's military has been modernized and improved. The US was shocked that all the great military hardware we gave to Georgia performed so poorly. While some of the reason for this is that the Georgians didn't know how to use it to maximum effect, some of it was also because we hadn't kept track of Russian improvements to military hardware the way we had in the Cold War. Your statements are a vast underestimation of Russia. It's no longer the crumbling debris of the Soviet Empire - it hasn't been that for about 15 years now.
ἡ δὲ κἀκ τριῶν τρυπημάτων ἐργαζομένη ἐνεκάλει τῇ φύσει, δυσφορουμένη, ὅτι δὴ μὴ καὶ τοὺς τιτθοὺς αὐτῇ εὐρύτερον ἢ νῦν εἰσι τρυπώη, ὅπως καὶ ἄλλην ἐνταῦθα μίξιν ἐπιτεχνᾶσθαι δυνατὴ εἴη. – Procopius
Ummaka qinnassa nīk!
*MySmiley*