Attention fluther SEO experts... Does current Google read photo metadata and does my plan of action help natural SEO?

Hope someone can steer me in right direction…

First, how important is it that photo based web sites have full metadata embedded within in each picture? Let’s say a site with a couple thousand images on a couple of hundred Wordpress pages. If it would help, can the meta tags all be the same, or should they be different?

But the big question is about my plan of action, as described here:

I have, up and running, currently three web sites that fit the description above. I do not wish to share them here. They are client based. So each client has a photo thumbnail on front page, and half a dozen extra photos inside the posting.

I want to initiate a cooperation with each client to begin a linking campaign. So here’s how it will work, with the desire to promote natural SEO…

My company will create for each client, a Facebook page, and a Google+ account, in my company’s name. Yes, each will have an individual email account. That process will be part of the contract my clients sign with me. The client will have no control over the Facebook/Google+ account I create for them. My company controls it completely. Those accounts will have links to each client’s individual post on the Wordpress site. Don’t worry, these clients want, and are paying me to do this for them.

The clients, as a vested partner, are required to send notices out to their friends and family that they have new photos posted on our Wordpress site. New clicks are initiated from the Facebook/Google+ page and linked over to the Wordpress site. Each Facebook/Google+ account will have copy with keywords designed to teach the web where to go when those words are linked.

So assuming each client sends their FB/G+ links out, and that initiates clicks to the Wordpress site, would that help teach the web what my site is about, and naturally rise the SEO for those keywords?

Everything on the up and up. The clients understand completely what I’m doing and want me to do it. Nothing hidden. And this has nothing to do with their own personal FB/G+ accounts. My account will not be linked to theirs. But theirs may be linked to mine, at their option.

Any ideas?

Thanks.