Tried to list my blog, got the plugin activated and did all the settings right but I get thrown an error whenever I try to submit the blog.
I see no problem with yours on your end. The URL Postloop checks seems to be working fine, possibly an error in the code at Postloops end (which would need to wait for Ryan)
Indeed, it was a bug on our end and is now fixed. Try to submit your blog again, and you do not to update or reinstall the plugin...Just go through the regular blog submission form as if you've already installed and activated the plugin