Re the flash issue - people are pulling me up on not providing a full explanation here. I visited the Church 3 times prior to the wedding. Once on my own to walk round the grounds, to see what the light was like at the time of the ceremony on a sunny day. Then again with the bride and groom when I met the priest for the first time was able to go inside - again, it was at the time of day that the ceremony was to be held. My words to him were "...and I assume flash is a no-no?...smiled" for which he knodded and said yes. So it's not that I said "Please will you let me use flash because I'm ruined without it?" - I assumed not by default, as courtesy, as has been said, but wondered if he might be one of a very few who don't mind flash being used.
I then went again for the reheasel two days before the ceremony where he detailed which stages he'd allow ME to take photographs - he banned the entire audience taking any for reasons I quite respect. He did allow flash in the back room for the mock signing of the register. He also allowed it in the doorway prior to bride entering the full church.
So there was lots of pre-planning for this, and lots of discussion with the priest. Maybe I should have made this clearer but thought the one line of "flash was not allowed" covered the point.