We have a big course about hair particles in the archive: https://cgcookie.com/archive/styling-and-rendering-long-hair-with-blender-and-cycles/
It's a little old but still chalked full of relevant info. But yes, I'd like to do an updated version of that course sometime. Thanks for the reminder.
There aren't any plans to do ripped cloth at the moment, but it's certainly a topic we should cover in the future.
