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You could export the Webmaster analytics, make a summary of which pages tend to run good and which not. Based on that data you remove the "old" pages, and watch the effect. While your at it perhaps throw some new content towards it. Does'nt hurt.

Interesting case. I do have a website thats more then 10 years old and which belongs to one of my clients. He got struck by the typical wordpress comment spam, in short there where over 50k of comment links found in barely months, and that counter is still going up since google is'nt so fast in crawling half of the internet (yet).

It is true that google pretty much senses if something evil or phishy is going on. I was suprised that even with 10k of follow links with the worst (same) anchor all over the place left the ranking(s) pretty much in tact. But there's good tools like https://websiteseochecker.com/extract-url-to-domain/#arearesult for example where you could cram in dozen of links and simply get ONE url out of it instead of weaving through a thousands of URL's manually.

This made it pretty easy to finally cram all those links in disavow. Yes some do hurt; usually after a half day when i submitted a disavow list rankings became a bit better. But if your spammed with low quality keywords, pages and all that, and you did'nt had anything with it or it was the 'leftover' from another SEO company, it's good to manually put these in disavow and measure the performance of your website. Sometimes it can take up to 2 weeks even, so have a bit of patient.

Getting quality links towards your domain is one way to increase your popularity, the other one is just having good content overal. Wanting to rank on 1000 keywords is everybody's wish, but it's not so easy.

it's called a "Sitewide" link. Yes there's risks to that, as i had a client doing the same on 2 different websites, boosting the amount of incoming links to roughly 250k in less then a month. After that he got tapped, lost all positions, traffic went down significantly, we had to adjust links, and it took on average 6 months to 'recover' from that.

If you put up a 301 redirect, then in theory all the 'linkjuice' should follow the new domain. However if you do this now, and like for example give out the domainname in a few weeks, that linkjuice would be no longer passed because the 301 is removed. So in best theory, is to setup a 301 now, and start changing those links that originally point to that domain, and change them to the new domain.

It's intensive, but you should have done a bit more research when launching a new domain.

Is your page valid with W3C standards? https://validator.w3.org/

I mean if it's a spaghetti of errors then googlebot might encounter issues with that.

The quality of responses on this forum is kind of dissapointing. Anyway: the following 3 things apply here for any new and existing domain:

1: a good structured website

2: quality content

3: quality backlinks

If you manage these in a good way then the rest really will follow. Buying links or links with the intention to pass ranks is forbidden by google, and pretty much punishes your website for doing that.

A few errors is always within margin of what google encounters. Ive seen broken pages completely that would not even render properly anymore but yet still rank. I'm not sure i was just guessing; but perhaps you need to give it a bit of time. I dont know what is going on really, new domains kind of are dampened for a while in order for Google to keep the spammy domains out of the place really.

I dont believe such a thing that when you update a Google Disavow, your DA suddenly increases.

It's explained here on https://moz.com/learn/seo/canonicalization

I really dont understand what your trying to archieve. These are incoming links to your page(s) on your site? And you want to disavow it? You want todo something else with it?

If your page is blog.companyname.com/en/ then your canonical should be blog.companyname.com/en/

Index the images?

Put up a sitemap with the content you want to have indexed.

It's not so simple really to just go by numbers created by MOZ or A hrefs, as nobody really knows what google maintains as a standard in a situation like this.

The less outgoing links on a page or domain, the more powerfull a link on that same page or domain would be.