I'll have a guess at these, still working on the ones marked "?".
1)The seven deadly sins
2)Birth Rates?
3)Equal Rights
4)For ever and ever
5)Get under way
6)?
7)?
8)Go for it
9)?
10) Ice cube (thanks to Quiggs!)
11)bird in the hand etc (thanks to SDQ!)
12) 2 buses arrive at once (thanks to Hollins!)
13)?
14)?
15)Over worked, under paid.