Help with meanings

Hi everybody:
I have heard these sentences and phrases in an American Movie and can’t figure them out:
1-If any two maggots ever deserved to boil in their own shit,they would be…
2-It’s the oldest con in the book.
3-he’d bounce 'em like a bad check.
4-Let me stake you a roll of quarters.
5-what does it mean to do something for Christ sakes?

Thanks in advance