Does Esenthel only support the "normal" clothing system or does it also support "mesh cloth" ?
Mesh cloth is when you can convert a model/mesh to cloth.
This way you can model your cloth (pants,T-shirts) in your favorite modeling package and then convert it into cloth for use in your game.
And can cloth be created and set up right inside of the world editor or can it only be created through programming ?

I think this is a valid and interesting question that went unanswered for 2 years now. Does anyone know how this can be done?

There is a C++ tutorial for cloth mesh you can modify it for your own purpose.