Any ideas how to increase the Yandex Site Quality Index via onpage changes?

We have pages with lots of unique content that are ranking very well in google.
I am now considering to add towards the end of the pages widgets from the booking.com affiliate program and also from the affiliate program of two other accommodtion sites. These affilliate widgets would be placed far beyond our core content in the bottom 15% of the page. Each widget will contain a large number of links to the different accomodation options that booking.com or others offer. In our context this information would be indeed very useful for our visitors. Shall I be concerned that our google rankings may suffer due to google perceiving our site as less quality (or google misinterpreting our intent to generate traffic to affiliate programs) ? If google rankings would be suffering, is this something we would normally see in a week (most of our pages are crawled daily by google)  and then recover in a week when we would remove the widgets or would this generally be something that would affect the ranking over the course of a month or more? Shall I be concerned abou link dillution since my pages would now have a lot of links pointing to the affiliate sites, which could devalue my internal links? Any thoughts?

We migrated 4 days ago to https and followed best practices..
In search console now still 80% of our sitemaps appear as "pending" and among those sitemaps that were processed only less than 1% of submitted pages appear as indexed? Is this normal ?
How long does it take for google to index pages from sitemap? 
Before https migration nearly all our pages were indexed and I see in the crawler stats that google has crawled a number of pages each day after migration that corresponds to number of submitted pages in sitemap. Sitemap and crawler stats show no errors.

I have a page which is ranking already pretty well for a relative competitive keyword. 
Google also ranks us on first page for synonym of keyword we optimize the page for (even though synonym does not appear on our page). I am now considering to replace some occurences of the keyword in the page by different synonyms, in the hope that our ranking may further improve for these synonyms. 
However I am concerned that google may penalize me for keyword stuffing if I am using a wide range of synonyms of one keyword on our page. My plan is only to replace some occurences of keyword with synonyms. I am a bit nerveous here since page is already ranking quite well in a competitive niche. Any thoughts?

When searching for "Madrid hotels" in google I see that the top organic search results have one row of sitelinks. 
What can I do that also my site shows sitelinks if I am among the top organic search results?
Anything onpage that I can do to increase probability that google will show sitelinks? Strangely the text which shows as sitelink for SERPs from booking.com and tripadvisor does actually for most of the sitelinks not appear on the landing page (I also checked the source code).

We plan to add several thousand images to our site and we outsourced the image search to some freelancers who had instructions to just use royalty free pictures. Is there any easy and quick way to check that in fact none of these images violates copyrights without having to check image by image? In case there are violations we are unaware of, do you think we need to be concerned about a risk of receiving Takedown Notices (DMCA) before owner giving us notification for giving us opportunity to remove the photo?

We are now introducing 5 links in all our category pages for different sorting options of category listings.
The site has about 100.000 pages and with this change the number of URLs may go up to over 350.000 pages.
Until now google is indexing well our site but I would like to prevent the "sorting URLS" leading to less complete crawling of our core pages, especially since we are planning further huge expansion of pages soon. Apart from blocking the paramter in the search console (which did not really work well for me in the past to prevent indexing) what do you suggest to minimize indexing of these URLs also taking into consideration link juice optimization? On a technical level the sorting is implemented in a way that the whole page is reloaded, for which may be better options as well.

Capitalization of first letter of each word in meta description. Catches more attention, but may this lead to google ignoring the meta description then more frequently? Same for an occasional capitalized FREE in meta description. Anybody had experience with this?

How does decimal rounding of reviews  to stars work in ios appstore?
Starting from which average review score to get full 5 star rating? Duolingo has a 5 star rating, but I doubt that they really have an all time  review average larger than 4,75. In the google playstore their average of the android version is 4,6. Does anybody know how apple calculates the star ratings or has an URL reference where this is explained?

Webmaster tools indicates that only 25% of pages on our UK domain with GBP prices is indexed.
We have another US domain with identical content but USD prices which is indexed fine. When I search in google for site:mydomain I see that most of my pages seem to appear, but then in the rich snippets google shows USD prices instead of the GBP prices which we publish on this page (USD price is not published on the page and I tested with an US proxy and US price is nowhere in the source code). Then I clicked on the result in google to see cached version of page and google shows me as cached version of the UK product page the US product page. I use the following hreflang code: rel="alternate" hreflang="en-US" href="https://www.domain.com/product" />
rel="alternate" hreflang="en-GB" href="https://www.domain.co.uk/product" /> canonical of UK page is correctly referring to UK page. Any ideas? Do I need to remove the hreflang for en-US to get the UK domain properly indexed in google?

I remember that Matt Cutts recommended against interlinking many language versions of a site.
Considering that google now also crawls javascript links, what is best way to implement interlinking? I still see otherwhise extremely well optimized large sites interlinking to more than 10 different language versions e.g. zalando.de, but also booking.com (even though here on same domain). Currently we have an expandable css dropdown in the footer interlinking 16 different language versions with different TLD. Would you be concerned? What would you suggest how to interlink domains (for user link would be useful)?

We are building URLs dynamically with apache rewrite.
When we detect that an URL is matching some valid patterns, we serve a script which then may detect that the combination of parameters in the URL does not exist. If this happens we produce a 301 redirect to another URL which serves a 404 error page, So my doubt is the following: Do I have to worry about not serving directly an 404, but redirecting (301) to a 404 page? Will this lead to the erroneous original URL staying longer in the google index than if I would serve directly a 404? Some context. It is a site with about 200.000 web pages and we have currently 90.000 404 errors reported in webmaster tools (even though only 600 detected last month).

What would you recommend regarding links to "Top Products" and "Top Categories" in footer? Would you add them to give extra link juice to top categories? would you try to avoid category links in footer that are already in the header navigationor in the main content area to avoid linking twice from all pages? would you vary these top category links in footer according to main category

we have a couple of pages displaying a dot in the URL path like domain.com/mr.smith/widget-mr.smith It displays fine in chrome, firefox and IE and for the user it may actually look better than replacing it by _ or -. Did this ever cause problems to anybody?
Any statement from google about it?
Should I change existing URLs? If so, which other characters can I use in the URL instead of underscore and dash, since in our system dash and underscore are already used for rewriting other characters. Thanks

I read about some recommendations to noindex the URL of the site search.
Checked in analytics that site search URL generated about 4% of my total organic search traffic (<2% of sales). My reasoning is that site search may generate duplicated content issues and may prevent the more relevant product or category pages from showing up instead. Would you noindex this page or not? Any thoughts?

our online shop targets clients in the US and worldwide (same URL - no subdirectories - currency changes based on IP). when searching in google.ie or google.no for our site google displays in the SERPS "US" or "United States" after the URL for our site, but for most other US competitors it does not show the country in the SERPS. I deleted our google places listing 2 weeks ago, since I suspected it may be related, but no change so far. In google webmaster tools we have targeted the shop domain to United States, which may be another factor. Unfortunately we can not undo this setting since without it our google US ranking for the most relevant competitive keyword drops from position 8 to position 100+. Server location is in Germany which despite lots of US links and US contact info and USD currency appparently makes google think that the site is not targeting the US. Does anybody know what triggers the country name in the SERPS (google places or webmaster tools or other) and  can give advice if there is any way to get rid of it.