Why can I "view only" in Evernotes something I created in Noteshelf 3? I also can't add to it in Noteshelf.

[timben 0]

I'm using the Personal Plan so might that be my issue?

[gazumped 12,066]

I think the fact that Noteshelf is not Evernote might be relevant.  Why don't you ask them?

[PinkElephant 8,805]

It is quite normal that notes holding content synced from other apps are "read only". If I remember it correctly, Penultimate notes were read only as well.