Following some links from Asgelle's post I came across this to answer one of OP's first questions:
(in regards to a 9 man TTT)"
The simulation results were illuminating. Compared with the lead cyclist, the drag of the rider in the second position is reduced by 21%. The third rider feels a further small decrease in drag over the second, but from the third rider back all other cyclists experience almost identical drag."
From this:
http://www.deskeng.com/articles/aaabey.htm
But also in there is this:
"
Perhaps the most surprising conclusion is that, despite the full force of the oncoming air, the lead rider experiences lower drag than if he were riding an ITT at the same speed. The drag coefficient of the leading TTT rider is 0.277, while that of an individual rider is 0.285. This occurs because the second place rider reduces the influence of the lead rider’s wake, increasing his base pressure and consequently reducing the drag force."