If you plan on translating a part to another language, I would use the hreflang tag to tell search engines that two pages are identical, just in different languages. Then search engines can serve the correct version of the page to whoever is searching based on their language preferences.

If a nice chunk of your customers prefer English, I would look into creating a English version of your entire website.

What do you mean?

Like on site.com/pagea.htm there is a canonical set to site.com/pagea.htm? No harm in that. You should have a canonical URL whenever you want only one specific version of a URL.

Schema microdata is a type markup that results in rich snippets (bonus details in SERPs).

Other rich snippet markups include RDFa and Microformats

If there is no direct way for the crawler to reach the page, it won't be indexed + if the page is so hard to reach, it probably wouldn't pass much authority onto your site.

I'd still get the link if it's on a good website for potential referral traffic but wouldn't worry about trying to get it indexed.

Read these two posts... they cover everything.

• http://moz.com/blog/canonical-url-tag-the-most-important-advancement-in-seo-practices-since-sitemaps
• http://moz.com/blog/rel-confused-answers-to-your-rel-canonical-questions

To sum up...

1. 301 redirect all non-www urls to www versions (since it has a higher page authority) and add canonicals to all pages with the www version of the url
2. For all lower case / upper case page duplicates... pick one, set a canonical tag and 301 to the chosen case, make sure all your links point to the correct url case.
3. 301 redirect default.htm to your root domain - http://www.cheaptubes.com

Could you share more details?

What do the duplicate content examples look like? http vs https? www. vs non-www?

If the content is replicated on 2 domains, yes that is duplicate content and you should consolidate to one site via 301 redirects.

.com is king but if they are doing well with their .ca domain, I wouldn't mess with it.

Do they have the resources to manage two websites? Having a .com would help them rank in US better over a .ca - ideally the sites would be nearly identical (changing up small things like CAD vs USD, contact address/phone possibly, etc) and then linked up with hreflang markup.