will scraped content (directory) hurt my site if I dont index the copied content

Hello

I’m using Yoast with wordpress genesis theme and GeoDirectory. I have a question regarding scraped duplicate content (directory).

I have 500 pages and 30 blog posts with unique content on my website.
Now I want to add a company directory with 10’000 entries. Later, this directory will have unique content like company reviews, images and company description.

But for now I wanted to scrape another directory (yellow pages) to start having content in the my directory.

Question: will this hurt my website in google?
My idea is to mark NOT index and NOT follow all the directory entries at the beginning (just the company detail pages, but I want to index the category pages from the directory).

Whenever I update a company profile and make it more unique with custom post content, I will inform google (webmaster tools) and will index this single page.

Will this work? Will google ignore all the scraped duplicate content if don’t index it? And will Google only index the pages that I select? (only the unique content company profiles)?

Because a directory has many category pages and search pages, I dont want to block the whole directory. Just the scraped company profiles that are not yet unique / with added value. And once I added value to the company profiles I will index it for google.

Thanks a lot for your inputs!