It's not blackhat SEO, and it's very common to create separate domains for the means of SEO. You can even use the same IP address (so you don't actually need a new host or new IP) and the benefit is still there. While it does help if the domains are hosted at separate locations, it isn't necessary.

Any of the articles that do belong on your company blog should be on your company blog. Everything else can go on the secondary domains. Just be sure that you develop the domains as you would your flagship website: with quality and attention to detail. Otherwise they serve no purpose other than for your SEO (no value to visitors) and they could be considered as grey/black-hat SEO.

Your secondary domains also become guinea pigs. You can test new services or link building ideas on them, and if they lose their rank, it certainly isn't good but it's not going to hurt your main domain. It's a layer of abstraction that will both protect your main website's SEO and allow you to start building case studies.

Personally I like to get whoisguard to mask the registrant of the domain, separate them all on different servers, and try to make them as unique as possible. (Tough in a specific industry, though..) I'd recommend you did the same.

Let me know if you have questions about this! Cheers.

I wouldn't slow the crawl rate. A high crawl rate is good so that Google can keep their index of your website current.

The better solution is to reconsider your hardware and networking setup. Do you know how you are being hosted? From my own experience with a website of that size, a load balancer on two decent dedicated servers should handle the load without problems. Google crawling your pages shouldn't create noticeable overhead on the right setup.

You should have both. Keep the paged navigation at top, but keep the infinite scroll. Now you have the best of both worlds.

Although, I don't think the infinite scroll would end up 'delinking' thousands of pages. How often do you see store.com/category/page/6 in results, anyway? If it's a popular term, it's going to be for the main category landing page.

Serving up different content to Google is always a bad idea unless you have a good reason. This problem doesn't qualify.

You're essentially asking if sitewide links are OK. Yes, they are.

Marcus makes a good point: if any of the pages are poor in quality, you'll notice a decline in value. Your priority should be ensuring all of the pages are high in quality, or at the least noindexed. The problem with WPMU was that they can't control the quality, so they just took the links out. Sounds like you are in a position to keep the links, but do a bit of cleanup.

Ask for a link in exchange for allowing websites to embed your graphic.

Check out Creative Commons licenses and pick the one that works best for you at the following link, and make sure the websites are made aware of the license:

• Creative Commons Licensing

Make the link modest so that the websites don't mind keeping it. Also consider asking that the image links to your website instead of a caption text, or give the website an option to do either.

Crawl your infographic or widget with a GoogleBot simulator if you aren't sure if Google will pick up the link. Although, you shouldn't have a problem doing what I described.

You can hide a link behind the image, but you really shouldn't be trying to hide links. Just stick with my advice and you should be golden.

Good question! Cheers.

Unless the layout was changed or things went wrong, no. I've migrated maybe 50 websites over the past year with no ill effects. Any that did, occurred because something went wrong (htaccess issues, extended downtime) or because there was a design change. In the case of the latter, rankings return any time between a few days to a few weeks. (Assuming the markup/content is still good)

Perhaps the better solution is to check referrer data in the header of your new domain, and show a brief note at the top of the page if it's from your prior domain. This has the benefit of not annoying your visitors with a wait time (a big deal) and you don't have to count on a workaround being fine with Google.

Simple to do in any web language, let me know if you need help.