As DeDaan has written, playing influence into the Chinese Civil War is about more than activating events: the China Card is very important for handling DEFCON suicide cards and other troublesome events.
Regarding balance, I think that between players who are still learning strategies, the game is relatively balanced, with lucky dice rolls or card draws having a bigger impact if they favor the USSR player (in other words, the USSR is more likely to win if luck goes his way, while the US player is just likely to enter the Mid War in a better state).
However, if both players are very experienced, I think the USSR has a definite advantage because it is much stronger in the Early War. The Chinese Civil War, Optional Cards, and extra US starting influence (though not in the rulebook) are methods of making the game more balanced. Players can use any of them that they see fit, though using more than one will probably cause an imbalance in favor of the US player.
Regarding balance, I think that between players who are still learning strategies, the game is relatively balanced, with lucky dice rolls or card draws having a bigger impact if they favor the USSR player (in other words, the USSR is more likely to win if luck goes his way, while the US player is just likely to enter the Mid War in a better state).
However, if both players are very experienced, I think the USSR has a definite advantage because it is much stronger in the Early War. The Chinese Civil War, Optional Cards, and extra US starting influence (though not in the rulebook) are methods of making the game more balanced. Players can use any of them that they see fit, though using more than one will probably cause an imbalance in favor of the US player.