Just noticed that there are spellblight feats in Ultimate Magic, but I don't think judges have approved spellblights? I'm not really interested in spellblighting, myself, but thought I'd mention it.
I added a spellblights exclusion to feats. Eventually, I personally want to look at spellblights for hostile terrain around elven gates and in the "badlands" type environments. But that will wait until after we have UC processed. They just look so much more flavorful than the general bestow curse spell.
Spellblights around elven gates sound kind of cool, but given that elven gates are probably for level 6+ characters, you've got some time before you have to worry about that.
NO to Antagonize, item creation feats or helpers, or to spellblight feats (for now). YES to everything else.