Brian,

i explain both ways as you may loose ratings in SERP. If you're sure that 1st isn't the case we're talking about then good for you.

The problem is N:2 data was shown in SERP using different methods. Example: http://www.mobiliodevelopment.com/pdf417-barcode-standard/ go in SDTT and look this url for rich snippets. There are 0 structured data except head metas. Now go back in SERP and look for "pdf417 standard" this article is maximum on 2-3 page if isn't on first. You can easy see "Mar 2, 2012 - PDF417 is a 2D barcode standard."

This is proof that you can have data w/o rich snippets. Now back on your problem. If you remember i talk about someone who lost his star reviews for year and they're back. I suggest this guy to go and ask here:
https://productforums.google.com/forum/#!forum/webmasters
Guess? Nothing happens. And this was 11-10 months ago.

That's why you need to check and recheck your implementation just to see that everything is correct on your side. This mean technical implementation and logical implementation. Then you may looking for support in link above and prepare for waiting with patience.

PS: I can take a look too but need url to inspect this site.

Mobile dev here!

So for all stores (AppStore + GooglePlay + Microsoft Marketplace + Amazon App Store + etc) algorithm is simple - they calculate ALL ratings on all versions. Some of them only for local store, other for global.

Example Duolungo:
https://itunes.apple.com/bg/app/duolingo-learn-spanish-french/id570060128?mt=8 <- this is in local Bulgarian Market. 4.928 in 9 ratings.
https://itunes.apple.com/us/app/duolingo-learn-spanish-french/id570060128?mt=8 <- in US market. 4.791 in 4068 ratings.
https://play.google.com/store/apps/details?id=com.duolingo&hl=en <- Worldwide. 4.648 in 2343538 ratings.

As you can see sites provide correct review rating to Google but they rounding it. Probably your guess for over 4.75 is correct. There isn't official explanation from Google about this. Some sites showing 5 star rating system. Other 10 star - 0, 0.5, 1, 1.5, 2, 2.5, 3, 3.5, 4, 4.5, 5. For other it's complicated because i have seen even results as 4.2 and this is 100 star rating system.

Get iOS or Google Play link of app and paste it on SDTT (Structured Data Testing Tool).

That's all. In SDTT they're even deep than 3 points...

TL;DR - YES

Long story - i'm author of similar desktop tool called SEOPingler:
http://www.mobiliodevelopment.com/seopingler/
so anyone you can use to ping anything. And bots are coming within second or two. This works perfect.

The problem is when you use this to ping many URLs (like 10k-20k). At some time this stop working and ping API endpoint receive your request but i can't see that bots are coming. This mean that there is some threshold that if you pass it for IP and you're temporary blacklisted. I also heard (but i can't confirm this) that this temporary may vary due previous usage. For me this isn't problem because users can blacklist their own IPs. And they can use hotspot wifi internet or VPN for continuing pinging.

But on server this will be HUGE problem because you can't switch IPs on-fly. And no one can guarantee how long your IP will be blacklisted.

Seems as related to AJAX crawler escaped fragment.

You should see why bot is trying to crawl normal pages with deprecated method. Please see "incoming links" to this 404 in SearchConsole to see where is root of this problem and fix it.

Yes, it's possible. I have example that on same host i host few sites that can rank on same keywords in SERP.

But you should watch for some spam sites on same IP:
https://www.youtube.com/watch?v=AsSwqo16C8s
there is example 26k vs. 1.

Update:
So few sites can rank. But when you try to rank much more then you can trigger some algorithmic filter (i can't find hangout where this is explained) because ranking engine will start to demote you. Since you have time to invest in few sites you should focus on single site. It's like quantity vs quality debate.

Links is "All links to this page including internal, external, followed, and nofollowed".
It's same number as if drop this URL into OSE where it's count as "Total Links"

Usual .htaccess mess... WHY? Because of flags:
https://httpd.apache.org/docs/2.4/rewrite/flags.html

As you can see there are few flags L, R, NC and other. But we will focus on L and R only:
R - redirect. This make 302 redirect but you can specify other response codes between 301 and 399. Example R=301.
L - last. This flag causes mod_rewrite to stop processing the rule set.

Let's go back on your file here is structure:
W3TC cache setW3TC compression set
W3TC CDN
W3TC page cache
WordPress handler - with L flag!
Redirects
Force non-www

What is the problem? The problem is that after L flag - everything is stopped. This mean that www and non-www works and no redirect between them. You need to make changes in your file as this:
Force non-www
Redirects
W3TC
WordPress handler

And check and recheck everything one more time. Including redirects.

Yes - you can!
https://support.google.com/webmasters/answer/93636?hl=en
Just follow instructions there. And check 301 redirects for correct location also canonicals, sitemap, robots.txt and links to static assets (CSS/JS) and link to pages.