1)
Yes, but it also can be 言ってしまった depending on the context.
2)
華やか / なり / し / ころ
華やかだったころ
3)
これが works as an interjection for emphasis, as same as これがまあ or これがまた. うまい means "to be good at~", of course.
4)
~(よ)うがない is an idiom, meaning "there is nothing/no way to~".
5)
~するところ敵なし: the strongest in doing
当たる means "to play a game with~" there.