White screen on admin posts page, memory errors on live site, corrupted posts?

My site is busted and I have reached the end of my WordPress abilities trying to figure out what’s wrong let along how to fix it. I have spent way too many weeks on this and I’m starting to get desperate. Really hoping someone can point me towards a solution.

I keep getting the white screen of death in the admin section when looking at posts. Everything else in admin & on the live site seems to look fine except for the posts affected. When looking at posts by the author with the most posts, it white screens at page 6 though it’s fine at all other pages. I managed to export everything to a brand new install (though I had to do it in lots of small batches despite it only being 770 posts on the whole site so something’s clearly wrong somewhere) and the issues persisted. Something seems to be wrong with those posts themselves as if they are corrupt somehow.

My theory is that it has something to do with Feedwordpress which we used to use heavily during the time period when the posts seem to get wonky (the infamous page 6) but I uninstalled the plugin so whatever it is lingers even after that’s gone, maybe meaning it’s related to how those posts were created by the plugin. When I have stumbled on these posts on the live site, they give memory errors when you try to view them. I’d be happy to redo or even delete those posts if there was some way to identify them for bulk deletion or access them at all but since I can’t even get that page of posts to load in admin, I’m limited there. We were using FeedWordPress to sync content between our Facebook page and the blog and that’s what those posts were, if that’s helpful.

Here’s what I already tried:
-disabled all plugins
-switched to the default theme
-moving the posts to a fresh wordpress install
-replacing the core workdpress files with newly downloaded ones
-regenerated the htaccess file in case it was corrupt
-Increased the php memory to over 200
-turned on debugging (but it never showed any messages so that wasn’t any help)

My original goal was to get the posts off this site, combine them into one of our other blogs, and just get rid of this site completely. Now that it seems to be the posts themselves that are the issue, I don’t know how the heck to proceed. I need to fix these posts to get them off this site.

Site is http://mylittleponycollecting.com I stripped it down to just the default template and no plugins while I troubleshoot this mess.
Running WordPress 4.2.1, Hosted through GoDaddy