The emphasis is "as much value."

When 2 or more links are from websites hosted on the same C-Class IP address, they're often owned by the same person/company, and therefore are viewed as slightly less diverse than the same number of links from websites not hosted on the same C-Class IP address.

A C-Class IP is simply the third set of numbers in an IP address: AAA.BBB.CCC.DDD.

The only difference here is that these links are missing a bit of diversity, but they're not bad and they won't hurt you simply because of the IP address.

Regarding your clients' sites that link back to you - yes Google can tell that they're all hosted together. If you use a custom nameserver that's the same as your primary domain, you can bet they know you're related. Those links are less valuable than if those sites were all hosted on separate servers, but rather than moving all of those client sites I would look into alternative link building strategies, since footer links as credits for a web developer aren't going to be a sufficient strategy for all of your link building activity.

As David mentioned, directions are good because they're rarely the same.

In addition:

1. Photos of the storefront, the inside of the store, and perhaps the kitchen or something like that.
2. Name of store manager if they're comfortable with that.
3. Schema.org markup of Address and phone number of course.
4. Reviews/testimonials for that store location, even if they're pulled off of Yelp.
5. Links to Yelp, Google Places, Foursquare, etc. for that store location.

There's a recent July 2012 statement by Matt Cutts suggesting that a couple sentences is plenty of unique content in a situation like this. Excerpt:

Eric Enge: Let’s switch gears a bit. Let’s talk about a pizza business with stores in 60 cities. When they build their site, they create pages for each city.

Matt Cutts: Where people get into trouble here is that they fill these pages with the exact same content on each page. “Our handcrafted pizza is lovingly made with the same methods we have been using for more than 50 years …”, and they’ll repeat the same information for 6 or 7 paragraphs, and it’s not necessary. That information would be great on a top-level page somewhere on the site, but repeating it on all those pages does not look good. If users see this on multiple pages on the site they aren’t likely to like it either.

Eric Enge: I think what site owners may argue is that if someone comes in from a search engine and lands on the Chicago page, and that is the only page they see on the site, they want to make their best pitch on that page. That user is also unlikely to also go visit the site’s Austin pizza page.

Matt Cutts: It is still not a good idea to repeat a ton of content over and over again.

Eric Enge: What should they put on those pages then?

Matt Cutts: In addition to address and contact information, 2 or 3 sentences about what is unique to that location and they should be fine.

So, I would focus on the Schema markup for the location, linking it to social profiles for that store, adding images or reviews as mentioned above, and making the page look nice. Anything else that is unique to that store is decent content to add.

You won't be penalized for publishing someone else's content on your site, however if it's published elsewhere first, your site probably won't get as much value for it. You'll always be in a fight with the other version for which one is seen as the original, and there's a good chance you'll lose against a local publication with a more authoritative website.

Ideally when I republish content from one source or another I'll partially quote the original article and then link to it. If I have to republish the whole thing, I'll start with a credit, such as "This article is republished from the original at LocaBusinessJournal.com/article-url/"

Hi Bimmer,

Thanks a lot for reporting your results.

I agree that it is easy for Google to figure out that if Page A 301 redirects to Page B (regardless of which domain each page is on), they can look up the Opengraph counts for both the old Page A and the new Page B and pass the value to Page B.

They just haven't publicly acknowledged doing so. That said, Google is a data monster, and OG is open. There's no chance on earth they're not trying to make the most of whatever of that data they can touch.

In regards to people changing the OG:url property, I know that there is a way to do that, but, I personally would prefer any new likes to apply to the new domain, and not to an old URL. If Google comes out and says they're passing social value of 301s, then I might reconsider that belief.

Thanks again for your feedback, very helpful!

I don't believe that tag causes an auto-refresh. Rather, it is used in combination with an auto-refresh to make sure that nothing is cached in the user's browser, which ensures that the entire page updated during the refresh.

If I recall correctly, sending "no-cache" info in the http header is a better practice that using a meta tag. To quote from http://www.mnot.net/cache_docs/#META:

"Meta tags are easy to use, but aren’t very effective. That’s because they’re only honored by a few browser caches, not proxy caches (which almost never read the HTML in the document). While it may be tempting to put a Pragma: no-cache meta tag into a Web page, it won’t necessarily cause it to be kept fresh."

I couldn't say whether this would affect your page in terms of SEO, but I also don't think there's a reason to use the pragma tag anymore, so in my opinion, it's moot.