The foundation for a Russian victory is to establish two separate opposite theater alliances. And by 'theater,' I don't mean East/West. Russia's two contentious theaters are Scandinavia and the Balkans. Russia must ally with the power on the opposite side from it in both Scandinavia and the Balkans -- that is, France and Italy. England and Germany and Austria and Turkey should be played off of each other.
It is important to note that the common statement that there are two triangles the board divides into (with Italy being a wildcard) is very much false. Italy and Russia are both wildcards: Italy can affect the West or the East, Russia can affect the East or both. I believe that Russia must affect both fronts to win the game.
With this in mind, Italy should be encouraged east and only east; there is no profit to Italy for an invasion of Germany, and Russia needs France as much as he needs Italy in order to win, so France and Italy cannot be fighting one another. Ignore the nonsensical claim that Italy can never attack Austria or else he will die by the Juggernaut; Turkey is very easy to stab after Austria is slain. Russia and Italy can choose which of Austria or Turkey they want to die first; I favor Austria, but either works. Be receptive to Italy here -- Russia needs Italy to be willing to help in order to conquer Austria and Turkey effectively, so hear the little green guy out. Whatever you do, ensure an Austro-Turkish alliance doesn't form; do not mention cooperation with Italy to either Turkey or Austria unless you can absolutely convince your short-term partner that Italy is only going to be used against the other player before you and the partner kill Italy. Austria-Turkey may only form out of necessity, but it is by no means a bad alliance.
The West is trickier. If Italy is encouraged east, then you have another quadrangle -- England/France/Germany/Russia. I feel like Russia must ally with Germany no matter what France wants to do. This quadrangle accurately parallels the east -- England is the Witch, like Turkey; Germany is the Corridor, like Austria; France is the Corner, like Russia; and Russia is the Spoiler, like Italy. So the EF v G dynamic is like the RT v A dynamic... with one HUGE exception. There is no western equivalent of a Lepanto, that is, no efficient or reasonable way for Russia to attack England like Italy can attack Turkey. This is due to the geography of the board and the starting units. Turkey takes a few years to get enough naval power to challenge Italy; England can be in Barents/Norway by A01. The only way Russia can attack England is with a Franco-German coalition, much like the AIR alliance against Turkey. This of course means alliance with Germany.
The only other real alternative -- because, again, an Anglo-German alliance, much like an Austro-Turkish alliance, can NOT be allowed to form -- is to see an attack on Germany. But think about this. If you made Italy absolutely incapable of attacking Turkey without Austrian help the way Russia cannot attack England without German and even French help, then there would be no reason for Italy to ever attack Austria. Helping a Juggernaut would invariably lead to Italy dying next. The reason Italy could spare an attack on Austria is because Turkey *can* be attacked by RI once Germany dies.
But Russia won't have that ability because of the split of St. Petersburg into separate coasts. If it could simply build a fleet in St. Petersburg things would be different, but the coast rule means that Russia must specify north or south -- and specifying north is basically mailing a declaration of war to Buckingham Palace. Russia has no excuse to build the fleets needed to attack England, and France cannot be expected to stab England alone and buy Russia time to build fleets and help. If an EF alliance kills Germany, then France has basically committed to continue the alliance and allow England to destroy northern Russia and any chance of Russian victory.
So what's a Russian to do? Keep England bottled up if not have England destroyed. If an active anti-English coalition can't be formed, then that means either an Anglo-German alliance has formed (BAD BAD BAD) or an Anglo-French alliance has formed. If the latter, then Russia must ally with Germany and keep Germany alive. This will stalemate the West long enough for Russia and Italy to progress in the East. Russia can either use the builds to build up sea power in the north and take the fight to England or stab Germany himself once Germany is arranged west and quickly grab so much of Germany that England will not be able to profit. Either way, if England is kept bottled up, then France can safely oppose England after Russia dies, which is exactly what Russia needs.
At this point you should see either a dead Germany or England and a dead Austria or Turkey. Now Russia should turn on the survivors with France and Italy. My preference is to maintain the French alliance to the end, as it's difficult to take France's gains in England and even some of his German holdings; while Germany is a corridor it's easy to hold from the west. Meanwhile Austria is easy to run through from either side, and Russia probably has enough troops around Turkey to make a good stab at Italian holdings there. But once you've gotten it down to France-Italy-Russia, you may well be a solo threat, and if those two ally then a draw is probably your best outcome. (Hence why France-Italy-Russia draws are actually somewhat frequent combinations.) But if you can use witty diplomacy to keep them from seeing you as a solo threat, you've basically won.
That's my thoughts on Russia. Your objectives are threefold: (1) prevent EG/AT alliances, (2) create strong, lasting alliances with France and Italy, and (3) keep England bottled up if not eliminated early.