Well, my Russia spiralled into chaos and revolt, drowning under the weight of excessive, unstable expansion and a little bad luck.
In the late 1770s, the populace of Russia began a religious strike - they were unhappy with the Republic promoting a free market economy (commies) prompting a strong rise in dissent country wide (+5 revolt risk). Shortly thereafter, Russia was afflicted by a trade crisis, forcing the administration to mint more gold, only adding to their already crippling inflation (inflation >100, +2 revolt risk). This carried on for a year, the national armies of Russia crushing revolt after revolt from aristocrats, peasants, Kazan nationalists, and anyone else who dared raise their banner against the state. Shotly thereafter the nation was gripped by further paranoia about the policies of the Republicans, causing further instability and loss of income (-2 stab, economy has no imploded from 150+ ducat to less than 50 ducat per month).
In an attempt to assuage some of the fears of the populace, the leader of the republicans is replaced by Arseniy Mikulinsk, a man of silver tongue, although somewhat diminished administrative and military talents. Despite his diplomatic talents Mikulinski is soon revealed to be phoney and unable to deliver on the promises the party has made (+2 revolt risk trait). In desperation and facing the ever higher quality armies of the nobles, Mikulinski calls the nobles to conferance and negotiates a peace with them. Russia will revert to the Noble Republic it was in the days of Muscovy, before Russia was born. Mikulinski would head this government of course, for he had the backing of the Russian national army and was prepared to reinstate the nobles past privileges.
The nobles accepted and it was done, although not without cost. The country was thrown into turmoil and the peasants were greatly displeased and were revolting as hard as ever. While a great diplomat, Mikulinski was not a peaceful man and did not see a peaceful resolution to his peasant problems. He promptly called his generals together and instated a military dictatorship (Republican Dictatorship), refilled his armies fundies and slightly curtailed the new privileges of the nobles. To fund his armies he took vasts loans from overseas powers and minted vast amounts of gold domestically, heedless of it's long term effects on the economy.
Soon Russia was bankrupt, it's armies significantly smaller, and still it was a backwards, volatile nation full of revolting peasants
(abandoned game in the year 1791)
Learned a lot from this game, such as bigger is not always better, and not to get too crazy with colonising because the maintenance costs can get out of control.