Blind Obediance really only hurts hasty creatures. Detention Sphere only really hurts you if you may multiple guys with the same name out at once. Oblivion Ring only can hit 1 of your guys.
I'd be happy to see someone waste room in there deck with Abundnt Growth.
Sphere of Saftey hurts with that kind of nutz enchantment draw though. At that point I'd be clicking into Burn mode with R/x decks and with B/x decks I'd probably be picking apart there hands in games 2/3 to make sure they never played a Sphere of Saftey.
But it's not something I'd be concered about. 5 lands and 5 enchanements (even with 2 being removal) is a lot of cards. Plenty of oppertunity to see them wiff a land drop if they kept all 5 enchantments and a 2 land hand, and Aggro decks punish inconsitant plays. I've only lost to Sphere of Saftey in RTR Block Constructed, and even then only because they got 2 of them on line and I couldn't answer there blasted Azorius Keyrune (and they had dealt with my Deathrite Shamans (all of them, each with their own Dention Sphere).
Sidebaord in some burn and fire away while adding in some black extort for extra value. This is an impossible matchup if you want to bash with creatures. But all their time spent ramping up enchantments are totally sucking wind if you ignore them completely.