Waste of skin — a person so worthless that it’s a shame they’re taking up perfectly good skin that some poor burn victim could be using
Waste of oxygen — see above
Jump out of your skin — be extremely startled
Save your own skin — protect yourself rather than trying to help other people
Enough to curl your hair — shocking or terrifying
Rome wasn’t built in a day — it takes time to create great things
An embarrassment of riches — too much of a good thing
Better the devil you know — stick to the familiar rather than risk the unknown (1539)
Kickass — forceful, aggressive, impressive, cool, great, exciting, awesome
Copy that — roger! or I understand. (military radio communication)