Its self explanatory. (Smurfing is high rank players on low ranks party's)
If anything it's encouraged.
Not really, as it's hard to prove when someone with experience makes a new account. Deranking is a part of the game so as far as I know, it isn't bannable; problem is, 3 gen strategy is a part of the game but is bannable if it goes on for 10 minutes straight, so who knows.
How is that guy banned in less than 30 minutes?
I think the thing is why he got banned