I think a lot of us has been where you're at right now, as long as you got the main shots, bridle party, parents with the couple, groom+best-man tossing the garter and first dance chalk the rest up to lesson learnt.
As for focusing, it may have been something other than the lense itself, can't comment on the flash.
All said and will be said, just remember you learn from your mistakes; it's just sometimes it happens at the wrong times. The good news with all this new software and digital photography, some of those bad shots maybe recoverable
