My take on slow japan first.
Attack FIC
3 inf, 1 fig Kill the units if possiable if Fig lives land in Sinkiang.
Kill transport in SZ59
Attack New guniea, Australia will fall soner or later anyway, if succesful its annoying for japan.
Also attack japanese sub with your sub. (kinda moot but anyways )
As russia you should have stacked 6 inf in Buryatia, and sent 2 arm from Russia to Yakutsk (i usually open with west russia belo attack and 3 inf, 3 arm Buy.)
The easiest way to cripple japan is to kill of it´s land units and make sure there are to many targets.