I note that my RSS feeds are processed only one at a time. Sure enough, in your code, I note:
// @TODO: Configurable limit
$limit = 1;
Do you plan on addressing this? I'd like all of my feeds to be processed every hour, not just once an hour. With more than 24 feed sources, that means they don't get processed every day. And I'd prefer to not make the cron call happen more often.
$limit = 1 is kinda a hack, no? :-)