1) If he wanted to attack Germany,he would have done it in may/june 1940 when the WM was busy in the West .
In May 1940, Stalin believed that the war in the West that was just starting would be a long one, essentially a repeat of the 1914-18 Western Front. He considered that by the end of that war, lasting several years, both sides would be exhausted and ripe for revolution, while the Red Army would have been modernised and strengthened, and in a position to move westward to assist the revolutions in Germany and France.
The rapid German victory in the West took Stalin by surprise and frustrated his strategy, since Germany was not fatally weakened while the Red Army was not yet strong enough to challenge Germany militarily. From that point on, Stalin adopted a policy of building up the strength of the Red Army as quickly as possible (the re-equipment program was scheduled to be completed by the spring of 1942), while simultaneously trying to weaken Germany by cutting back and even temporarily halting the flow of oil and other supplies to it.
It is likely that Stalin would not have chosen of his own accord to launch a first strike against Germany in 1941, since the re-equipment program would not have been completed. However, it is a fact that by May of that year Timoshenko and Zhukov had drafted a plan for a pre-emptive strike against the German forces in Poland, and that can only have been in response to an order from Stalin.