diigo is a bookmarking service.  I use it myself, largely to save things I find online for later reading in a cross platform manner: ie I spot something on my phone and diigo it for later reading on my laptop.

diigo has a few features that similar services don't offer, which I why I switched from evernote.  Groups sharing is a win for me as are some of the annotation features.

You can make your bookmarks public as well, which is where those backlinks you are seeing probably come from.  Are they all from a couple of users or seem to be quite widespread?

Social bookmarking as a link building means is pretty old hat to be honest and generally not too effective. In fact too high a proportion of this could be risky.  I think that most people would rather have one nice authority link than a load of diigo links.

Short version then: good service, but not for link building.

You can do these with forwarding etc.  However that isn't the most efficient way.

What you want to do is to "park" the old domain on the new one.  In technical terms this means pointing the nameservers at the new hosting account and ensuring that there is MX record for them.  Most hosting companies do this for you or have a built in tool. It's very easy and is usually called "domain parking", "domain mapping" or "add on domains".

Doing that will ensure that visitors (and bots) visiting olddomain.com will be served newdomain.com

With that working you can just add an .htaccess rule on newdomain.com to ensure that it 301s correctly to newdomain.com . The same directive can tidy up all your subdomain woes at the same time!

This method has the least points of failiure and creates the fewest redirects. It's also generally the cheapest and easiest to manage. Win!

I've only looked at a handful of pages / categories, but I am not sure that you are doing yourself too many favours.

In SEO terms I think that you are undermining your unique content pages.  By repeating the unique content from the product pages on to the category pages you are effectively introducing duplicates.  Yes, it is your own content, but spreading it across those pages is unlikely to do you many favours.

More importantly it's also pretty confusing in places.  Some of those categories are quite off putting.

What would I do?

1. Remove those descriptions from the cat pages
2. Add category descriptions
3. Try to flesh out the product descriptions with more unique content and keep an eye out for those that duplicate each other.

I hope that helps.

I frequently use the page number in titles.  It's not a bad solution where you want them all to get indexed.

Keep an eye on whether it affects CTR from the results though. I also like to ensure that there is always a link to the first page of results. This is useful for the user and also helps push more authority to that first page so that it is more likely to be the one that appears.

There is a chrome extension called "scrape similar" that is useful for doing small batches of stuff like this. However it does have a couple of limitations in that you have to view each page & google will not show you all pages of a large domain. However it is quite easy and effective for sites with under 1000 pages.

https://chrome.google.com/webstore/detail/mbigbapnjcgaffohmbkdlecaccepngjd

The process can be sped up using other tools.  I use tool that is designed for black hat forum/comment spamming to do SERP scrapes like that.  Even if I did such spamming (I don't), I don't actually think this is a very good tool to do it with. However it is rather good at scraping results from google. However, again you are limited to how many results Google/Bing choose to show you.

If you need a bigger list then log files might be the way to do.  You can get a list of all crawled URLs for any particular agent (including the likes of googlebot) from your server logs.  Some hosts limit the size of these, so it might be worth checking before you start.  However the data does get collected.  The downside here of course is that you need access to the logs.

Of course crawled is not the same as indexed. Once you have that list you might need a further step to see which is indexed. Possibly cross-referencing it against google analytics landing pages or querying the google cache for that page (SEOtools for Excel from Biels Bosma is good for this).

Similarly, if you have a definitive list of the URLs on site you could start with that list and query which are cached.

Harder than it seems isn't it? Hopefully one of those methods will put you on the right track.

You didn't get an A grade when I checked it I am afraid.  However results will depend on what keyword you enter. When I used the URL you gave above plus the keyword "towel" that gives you a B - mostly downgrading due to keyword stuffing.

The word towel is mentioned 105 times on that page.

This is clearly too much. Who ever put the CMS together probably read something about SEO written in 1998 and thinks that is the way to get results. Definitely get this addressed.  Getting your CMS output correct on those template pages is vital.

Tabs can work well. However they do have to be thought about.  At the moment it seems that the main purpose of the tabs is to hide keyword stuffed content - which doesn't help anyone.  I actually quite like tabs for product pages, however I'd still have the most important information visible on the default page. However, that is personal opinion.  A single page can work equally well and can actually be useful in terms of forcing you to edit and prioritise the information on that page.