seo – Content – Duplicate Issues

I have a series of websites in my state, targeted locally for each county. Most of the information, content / structure are identical, with slight variations depending on the country concerned. I would say that 90% of the content is the same, especially sections like FAQ, About Us.

There is a main website and then "micro-sites" that target the counties.
I would appreciate advice on the following:

1.) From what I've figured out so far, Google will not necessarily put me on duplicate content from one domain to another (the content is original and written by me, so I do not worry about the plagiarism.) But I'm not sure that it's better to change / reformulate the 50% content text?

2.) From the point of view of the brand, am I starting to make references to the parent company? This means that certain forms and sections of content such as FAQs do not change, should they return to the main site? My concern is then that the micro site may be too thin and confuse users.

All locations will have a local office.