The girl turning up with a cracked visor and them Amy apologising for shooting her... was that just a sort of "oh blimey, I'd better put a line or two in about that" or was it more significant?

No idea. I thought it would be more important since it was last week's cliffhanger, but maybe that was just setting up the little girl's regeneration?

What you're saying about the Amy/Rory/Doctor pseudo-triangle... I have the same issue with River shooting the Silence(s?). It is kind of badass, and I wouldn't bat an eyelid if it were on TW, but on DW? After RTD that kind of off-hand violence is a bit of a shock.