Google Panda: What gets affected/ What doesn't?

So I've been researching about Google panda A LOT these days since my page1 Google site went down to page 2. According my research these are the 3 biggest things I've learned from reading all over the place:

-Article submissions sites(like ezine, goarticles,etc) will not be very effective.
-backlinking techniques like scrapebox, Xrumer will not be as effective??
-Getting domain names that match the keyword isn't weighed as highly as it used to be

Can anyone add any truth to these? Is Google going to start penalizing for backlinking techniques like Xrumer, Scrapebox, etc???

Anything else you guys would like to share about your personal experiences with Google Panda?

I had a bunch of sites that were ranking in top 3 or even ranking #1 for it's main keyword all drop off to page 2 and beyond. These were micro niche sites, most being EMDs, all unique content, some with just one article on the homepage others with 5-7 pages (not including the privacy, about us, etc. pages) of content.

I can't pinpoint on what caused the decline on these sites. These had various types of links from blog comments, article directories, forum profiles. They were never spammed with scrapebox or xrumer. Most of the links were manually done. The only thing I can think of that is common on many of these sites is that the sites had no activity as far as new backlinks or new content (like for 6 months). I don't know if the drop was because Google thinks the sites were no longer as relevant since no new content was added or new backlinks coming in.

A few did not drop at all, but these sites hardly got any traffic in the first place and are still ranking at the #2 spot with only just 1 article on the homepage. It seem like all the sites that were getting decent traffic and making the bulk of my income got hit.

Right now I've started to do more backlinking to these sites to see if that starts to bring them back to the old rankings. I will try to start to a few new posts as well to each site to see if that will help as well.

Anyone whose sites dropped from top of page 1 to page 2 and beyond able to get their rankings back or have at least improved them again? What have you done?