Are praying and listening to stories supposed to make dwarf non-idle?

Solution 1:

Yes, the idle counter is meant to show you how many dwarves are sitting around waiting to do something. The new "jobs" like listenting to stories are essentially the new way that dwarves sit around and socialize so the idle counter has become less reliable than it used to be because of how much more common socializing is. My guess is that toady will eventually change it to include socializing dwarves to be a better measure of how many dwarves are working.