With the changes to AC and to-hit, I'd like to suggest changing these bard abilities. I have 2 bards (that I love to play), but these changes make the to-hit increases they bring much less important (sometimes not important at all).
I suggest changing the to-hit part of their songs to a percentage. Just add this percentage into the 25% proficiency part of the to-hit calculation. I think this would allow a bard to always be a useful and wanted party member, without being OP.
I also suggest changing Inspired Attack (I know the Enhancement pass isn't coming for a while):
Inspired Attack I/II/III : +1 / +2 / +3 attack bonus (2 / 4 / 6 AP)
Inspired Attack I/II/III : +1% / +2% / +3% attack bonus (1 / 2 / 3 AP)
I also suggest some more support for healing focused bards, but I think there's already enough threads about that.