Russia, A bit too strong?

[The Witch-King]

Also keep in mind that Sweden never fought Russia when Russia was at it's best. Sweden was that little annoying bloke who ran up and punched you in the back of the head while you were fighting three other blokes on the front lawn and your wife was yelling at you. No matter the period of history, Sweden should never (without some massively ahistorical empire) be able to stand toe-to-toe with a Moscovy/Russia of any considerable size.

I'd say wait until Russia is suffering some peasant's war/time of troubles event (I just recently started a game as Russia in 1613, OMG most frustrating thing ever) and capitalize while everyone in the world also attacks them.

Indeed. But that strategy was used by Russia in return too. At least until after the Great Northern War - which saw the end of Sweden as a great power - both Sweden and Russia constantly tried to sucker-punch each other. But after 1721, Sweden just wasn't in the same league anymore.