It sounds like there are a number of issues going on here and it's quite hard to envisage everything.

Having captions indexed as snippets requires the page to be setup in such a way that Google can use them. But remember that in terms of what Google shows, they will deliver what they thing bets suits the search query.

In terms of images being indexed, have you thought about having an image sitemap, or having them included in this? However, I wouldn't be setting a canonical from slideshows to base pages as this sounds like it could cause you a load of headaches.

Duplication is hard to assess as there could be a number of reasons from this, including incorrectly set canonical tags, indexed pages or other semi-technical issues.

Personally, I wouldn't be looking at slideshow images as something to be indexed, but I would be using some of these images in the page itself. This is just what I have found in the past.

-Andy

The problem that I have found with this in the past is that Google sees the whole page and not the images. I found this to be more of a limit of Wordpress.

However, you could use an image sitemap and see if you can get them indexed that way?

-Andy

Hi Mandy,

If I am understanding what you want to achieve, you could always try Screaming Frog Spider. When you do a crawl, it will show you all of the pages, and then you can click on a page to see links that lead from that page.

Also, you have an option of an advanced report that will show you all of the OutLinks from a site. Very useful tool.

-Andy

Very welcome Tom - hope all gets sorted.

-Andy

As already indicated, there is no harm in having your business listed on a directory, just don't do it for SEO purposes.

It can help when you are looking to increase cocitations (Yelp, Yell, at al) and to promote your business through niche sites is no problem either. Just tread carefully.

-Andy

I have used this one with no problems for a long while now:

XML Sitemap Generator for WordPress 3.2.4

So Apartment Therapy are selling links? Tread carefully with this, because you have announced that you may pay $10k for writing an article that contains lots of links back to your site. If Google get wind of this, you could spell a whole heap of trouble for yourself.

Just as a side note, $10k will buy you a lot of very good organic SEO and link building that won't carry the risk.

-Andy