I would noindex the categories or clean them up + optimize them... seems like most categories only have 1 post and the categories have more internal backlinks than the posts.

I would combine categories by brand or something and add a unique paragraph of text to the top with phrase(s) you want to rank for. Alternative is to noindex the categories which should help your posts rank - less duplicate content.

Correct. They won't be indexed but are still followed.

"I recently read that another Mozzer saw a great improvement after disallowing all query/parameter URLs" - do you have a link for this?

Canonicals should be enough but Google does mess up and the more clues you can give them, the better.

You can also manually tell Google parameter meanings (if you check out your parameter page now in search console, you should see all of the parameters they've detected for you - you can just change their meaning).

I don't see any harm in disallowing parameters via robots.txt. They will still be crawled and internal links followed, just not indexed in serps.

You should create separate events for each event you have (even if the location is the same)

from https://schema.org/Event --> "Repeated events may be structured as separate Event objects."

Check this: https://www.seroundtable.com/google-hidden-tab-content-seo-19489.html

1. If you want to deindex all PDF files, I recommend using the x-robots-tag in .htaccess - https://yoast.com/x-robots-tag-play/

2. If the PDFs are pdf versions of existing pages, I would set canonicals to point to the URL you do want indexed (#2 on http://moz.com/blog/htaccess-file-snippets-for-seos )

Not allowed. See https://support.google.com/merchants/answer/2770285?hl=en

Are you sure? On https://support.google.com/webmasters/answer/6033080?hl=en&ref_topic=6033084 it says: "No need to submit a change of address if you are only moving your site from HTTP to HTTPS."

I dont think you are given the option to select the same domain for change of address in GWT.

Looks like you are doing everything right (set up 301 redirects, updated all links on the site, updated canonical urls) - just need to force the crawlers to parse those pages more. perhaps crawler is hitting its budget before it gets to recrawl all of your new urls?

You should also update your sitemap as it contains a bunch of links that look like: https://www.gomme-auto.it:443/pneumatici/estivi/pirelli/cinturato-p1-verde/145/65/15/h/72

I recommend creating several sitemaps for different sections of the site and seeing how they are indexed via GWT.

use  the_title();  for the H1 tag instead

Not sure what that other code does... if(!wp_title("",false)) { echo bloginfo( 'title');} ?>

if no title set, show blog title? what pages would this affect?

The plugin doesn't affect any H1 tags at all.

I'm guessing that you are inputting the SEO title into the wrong section. Name you post whatever you want regularly (this will be your H1), then scroll down to the Yoast section and change the field called SEO Title (which will only change your title tag).

If its doing something else, then the problem is with your theme.