All of this iCloud Pages 5 stuff and...

how hard would it be for a modern word processor (Pages 5) to export and email directy to PDF?

Create document in Pages 5, click "PDF and mail" under the share button -- send the file to everyone working with you that wouldn't have Pages and could possibly be using Windows and PC's.

Is that not a feature as important as "share" a Pages file via email or a link on iCloud?