I think that situation's a bit different - if you aren't interlinking and the sites are very different (your site vs. customer sites), there's no harm in shared hosting. If you share the IP and one site is hit with a severe penalty, there's a small chance of bleedover, but we don't even see that much these days. Now that we're running out of IPv4 addresses, shared IPs are a lot more common (by necessity).

Are you seeing the images getting indexed, though? Even if GWT recognize the Robots.txt directives, blocking the pages may essentially keep the images from having any ranking value. Like Matt, I'm not sure this will work in practice.

Another option would be to create an alternate path to just the images, like an HTML sitemap with just links to those images and decent anchor text. The ranking power still wouldn't be great (you'd have a lot of links on this page, most likely), but it would at least kick the crawlers a bit.

Yeah, normally I'd say to NOINDEX those user-generated search URLs, but since they're collecting traffic, I'd have to side with Alan - a canonical may be your best bet here. Technically, they aren't "true" duplicates, but you don't want the 1K pages in the index, you don't want to lose the traffic (which NOINDEX would do), and you don't want to kill those pages for users (which a 301 would do).

Only thing I'd add is that, if some of these pages are generating most of the traffic (e.g. 10 pages = 90% of the traffic for these internal searches), you might want to make those permanent pages, like categories in your site architecture, and then 301 the custom URLs to those permanent pages.

Alan's absolutely right about how canonical works, but I just want to clarify something - what about these pages is duplicated? In other words, are these regular searches (like product searches) with duplicate URLs, are these paginated searches (with page 2, 3, etc. that appear thin), or are these user-generated searches spinning out into new search pages (not exact duplicates but overlapping)? The solutions can vary a bit with the problem, and internal search is tricky.

There's nothing wrong with doing this, as long as the "title" attribute is accurate (DON'T spam it with non-relevant keywords), but I haven't seem compelling evidence that it acts as a ranking signal.

One thing I'd keep in mind is that a lot of your main nav pages aren't always great landing pages for search users. "About Us" is a decent landing page for finding out about your company (and that or the home-page should rank fine), but it and "Contact Us" aren't usually good bets for your non-brand keywords. It's often better to have a dedicated page targeting separate services.

I think it's fine to use keywords for the "Services" page, or you could split that page into specific services. Then, each service would have a keyword-targeted internal link and content. In that sense, think of your services like products - you branch from a main "store" page to categories to individual products. Done well, it serves both users and SEO.

I don't think there's a "right" answer here, but my observation is that microsites aren't doing as well as they once did. It used to be that, just by having more sites, you did better. Now, as Google seems to be testing the volume know on exact-match domains, devalues cross-linking, and is harsher on duplicate and thin content, it's a lot harder to support separate sites. Factor in that you're splitting your links, social signals and offline marketing/branding, and promoting two properties can really make you lose focus.

That's not to say it's all-or-none, though. Exact- and partial-match domains do still carry weight, and if the niche is unique and separable enough, it is possible to build a strong identity for it. I'd really look at the business side, though, for guidance. Is this a division of the business that really stands alone as a brand? If so, separation could provide broader benefit. If you're just separating for SEO, I'd generally side with keeping the unified site.

The issue with the redirects is that the weight of those pages only gets to exist in one place. So, if some of those pages have inbound links, a 301-redirect will kick start the new domain, but it will also take away from the authority of the old domain. In other words, you may not just lose the traffic itself - you may lose some of the main domain's ranking ability. That depends a LOT on the situation, though (it's hard to speak in generalities).