This is a great question and not easy. I would love to hear some others chime in. My guess is that splitting the pages immediately would be the best. Yes, you would lose the ability to do the change of address, but that really isn't essential. At the beginning, I would keep the content as similar as possible if not identical after the transfer (of course with different internal links).

The two sites you presented are wholly different cases...

1. Sorry, but m2beveiliging.nl was hacked...

Look at the backlinks you are receiving. They point to pages like...

http://www.m2beveiliging.nl/aysg/kaa3g0wy.html

Which no longer exist. But if we check the Google cache, we can see they are filled with

http://webcache.googleusercontent.com/search?q=cache%3Ahttp%3A%2F%2Fwww.m2beveiliging.nl%2Faysg%2Fkaa3g0wy.html&oq=cache%3Ahttp%3A%2F%2Fwww.m2beveiliging.nl%2Faysg%2Fkaa3g0wy.html&aqs=chrome..69i57j69i58.967j0j7&sourceid=chrome&es_sm=93&ie=UTF-8

The content translates to ... "Adidas soccer spike type, Adidas spike baseball order non-standard-size Free Shipping!"

2. http://www.keukensduitsland.nl/ on the other hand received a ton of directory links. I dont know if you, an employee, or the client themselves did this, but is doubtful that it was intended to be malicious. All of these directory links originated in the last few weeks, matching up with the search in referring domains and links.

• http://www.organicseooptimization.com/home_and_garden/kitchen/?p=28
• http://www.geohweber.com/home_and_garden/kitchen/?p=28
• http://systx-web.com/home_and_garden/kitchen/?p=14

1. The anchor pages aren't going to be indexed separately. If you are lucky, you might get a rich snippet from them in the SERPs, which would be nice. You can see an example of this if you search Google for "broken link building" and look at the top position.

2. Google likely has a crawl budget for sites based on a number of factors - inbound links, content uniqueness, etc. Your best bet is to make sure you have a strong link architecture, a complete and updated sitemap,  and a good link profile.

3. Google can't index the whole web, nor would they want to. They just want to index pages that have a strong likelihood of ranking so they can build the best possible search engine.

There are several tools that do this.

• http://www.alchemyapi.com/products/demo/alchemylanguage
• http://www.grepwords.com (tag-finder)
• https://northcutt.com/tools/free-seo-tools/keyword-extractor/
• https://developer.yahoo.com/contentanalysis/

Just to name a few

Well said. And on that note, I wouldn't trust the SEO advice of an email spammer

I agree with Josh on this one. There needs to be some reason Google should believe that the ratings on your site are legitimate. I can't be certain that third party sites like Yelp or Google+ are the source of that social proof, but it seems both plausible and fairly easy to detect for Google. It would be a sound place to start.

I believe you might be able to use List Mode in ScreamingFrog to accomplish this, however it depends on ultimately what your goal is to check for duplicate content. Do you simply want to find duplicate titles or duplicate descriptions? Or do you want to find pages with sufficiently similar text as to warrant concern?

== Ooops! ==

It didn't occur to me that you were more interested in duplicate content caused by other sites copying your content rather than duplicate content among your list of URLs.

Copyscape does have a "Batch Process" tool but it is only available to paid subscribers. It does work quite nicely though.

Great question, and I certainly heard the "will this hurt my seo" thing all the time as a consultant. A couple of thoughts...

• To my knowledge, there is no specific algorithmic feature that would lower a page's rank because of too long descriptions
• Long meta descriptions, however, may be truncated (as you pointed out) or ignored and replaced altogether by Google if they find a more appropriate subsection of text on the page.
• A succinct, well written meta description may help with CTR which itself may be a ranking factor
• Google has stated that they want you to write good meta descriptions, for what it is worth.

What I try and say to clients is "are you prepared to build a top 10 website in your industry". If they are sweating good meta descriptions, they aren't ready to compete in the big leagues.