Sorry for being rude but... If you offer code to host the service autonomously we can came and go, otherwise being just able to import/export feeds is lock-in:

Sorry for being rude but... If you offer code to host the service autonomously we can came and go, otherwise being just able to import/export feeds is lock-in: already read feeds, saved articles, UI etc are the lock-in elements, for a serious RSS user. If your target is just offering an aggregator like "Google News for the content you want", well, I can understand but for people who want to control their source of information, reducing propaganda and crap of modern websites/services, it's not a real option...