Well I think you were thrown a bit of a curve-ball when they expected many questions from you, having said that I think you could have phrased things a tad better:

1) I think "quantity over quality" naturally triggers a negative reaction from the listener - true as it may be. Maybe you could have gone with "are we focusing on high-frequency posting or more detailed, targeted posts". Something of the sort.

2) The question on company culture was a bit generic but I don't think it was bad per se. Maybe you could say do we lean towards the formal or casual side of things?

3) I think it's not a good idea to ask about leadership style - you're essentially asking your future boss how she is going to boss you around. For me personally I'd avoid going there at all.