Essential Features in a Feed Aggregator?

Hey, I'm building an RSS Reader / Feed Aggregator and currently looking for feedback and ideas on what features would users want.

I want to build a better alternative to Feedly and other readers.

My value proposition points are the following:

1) Modern design

2) Simpler use and minimalistic interface

3) Cheaper paid subscriptions

4) Wide feature availability in the free tier

5) Pocket-like browser extensions for saving urls to a Read Later section

6) Aim at the regular internet user so it's really seamless to get up and running (not like aaronpk's Monocle for which you need to setup your own Microsub server and stuff)

7) Highly customizable: shortcuts, colors, layouts and other options

8) Add a tool to make a feed out of any website (like an integrated http://fetchrss.com/)

9) Save articles as PDF for offline reading or sharing

10) Probably offering an in-app reader but I also want to emphasis the importance of reading content on the actual website to show support and 'live the real experience' just how the creator intended to (and not just my parsed content, stealing traffic from his site)

Should I give it a try or should I quit already?