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I agree with Gary, you should definitely go through all your links and be really ruthless in terms of which are the poor quality links. Anything that is on an article or directory website you can probably get rid of (apart from directories like Yahoo, DMOZ etc) and submit your disavow file to Google. If it is only your target keywords that have dropped then you have been lucky to escape a site-wide penalty but there is a good chance that this will be on its way so if you can clean up your profile sooner rather than later, it should help.

A 200 does mean "OK" - for that URL (note - not for the site). So, if you want the www. version indexed rather than the non-www version then you want http://www.keepsake.... so return a 200 response ("Yes - this URL is OK"), but you want http://keepsake... to return a 301 ("This URL is not OK. It has moved to http://www.keepsake... "). As I say, some of your URLs do that correctly, so whoever put the redirects in place understood what they were aiming for.  However the ones with the trailing slash don't. Is that a little clearer?

Start with the simple as Mike and Kevin said, there are numerous things before you begin looking at Penguin or any other algorithm changes affecting the results for drastic changes. Alex - while you may be correct, this is definitely not the best spot for Victoria to start.

Thanks so much for your feedback and insight. What I was thinking was that we would pull it in as being all about mums and their chosen topic. So not that different than About.com or wordpress.com where everyone blogs/talks on the same platform but all separately but I pull in the most commented/popular topics on the home page like a 'what's hot' sort of feature. Perhaps have a directory on all the different topics but everyone markets their own separate blog. So my options are: set up people with their own domain or have mumbloggers.com/blog1 (not calling it mumbloggers but using it as an example!) So really focusing on mums with a passion and interlinking them all if appropriate. If there is not much benefit from having it all on the same domain then I guess separate will be the way to go but am picking up that if I can get the above 'shared' domain to work then it would be far more powerful? Does that make more sense? Thanks so much

I would second the Screaming Frog tool, just used that yesterday and it's great! Might even buy a licence for it now. The free versions great though.