I agree with everything you wrote.. The separation was there, which is actually a compliment to our receivers considering that they were going against fantastic corners and a center-field safety. The drops were inexcusable, especially from our "impact player" Corey Smith. (Brief side note, did anyone else roll their eyes when Smith was listed as one of OSU's two impact players when we first went out on offense?? Guy hadn't even caught a pass yet at OSU)
I think in general people have to settle down on the position coaches. I think the coordinators struggled but the skill players were often in a position to make a play but failed to do so. Barrett himself relied too heavily on the long ball and never used his check-down receiver, which is supposed to be your blitz protection. Aside from some players who made glaring mistakes, I think this loss rests squarely on Herman's inept playcalling (relied too heavily on deep ball rather than slants, swings, and screens against a zero man coverage) and Ash's third-down soft zone defense.