Hi Firefax,
this error message looks like there is a problem when trying to connect the eShop for getting needed data. This service request the shop data (version, UTF-8 usage, db credentials …) for executing a campaign. There seems to be a problem using CURL.
Concerning your general questions about the EPL: I try to set up a wiki page describing all the EPL stuff, but this will take some time. But I’m on it.
Cheers, Bissie