The hyphen would be located between the mid and the century.'Mid-century'.
Yes, mid is not a word in itself, but acts as a prefix and so must be connected to the word following it, usually with a hyphen (although there are exceptions such as midday)
It does not need to have a hyphen! :)
No
It's not a word in the dictionary, so yes, use the hyphen.
I do not believe that multitasking is supposed to have a hyphen.
You typically need only capitalize after sentence-ending punctuation, which a hyphen is not.
no
No.
No
no
Yes, in-home does need a hyphen. It's two words put together to form a word for a different concept.