As to Warpstock Europe, I can't speak for why they always schedule their
event for within a month or so of ours.  We always seem to have ours
scheduled first and they always follow closely behind.  I have always felt
that this hurts both events, as I personally would love to attend the
European one, but its impossible for me to get away a few weeks after I
just went to the North American event.  But you will have to talk to the
WSE folks about scheduling their event.  We share the Warpstock name with
them and promote one-another's events on our web sites, but there is no
coordination beyond that.