The phrase is each to their own devises. (Note, the American spelling is 'devices', but the expression is well known in both England and the United States.)
saves nine
No,it is not an idiom. It means exactly what it says - "if the job is going to get done" with the implied ending of "I will have to do it."
"Still waters run deep".
Each idiom has its own origins - you'll have to look up the etymology of every one separately.
Similar to each other; of the same source.
If two people are "at each others' throats" there is hostility between them.
To close the door on something and or someone is an idiom. It means you are preventing something from happening and or ending an event and or situation.
Idiom is correct.
An idiom is a form of expression in a general group or culture. Something like 'It's raining buckets.' This doesn't mean there are literal buckets falling it just means it's raining hard. You most likely will have to define what each idiom means.
No, "As ____ as ____" is always the formula for a simile, a comparison of two thing to each other.
what is a idiom about a cat
"To be" is not an idiom - it's a verb.