Cepi, just add a toggle like:
"Make new incoming attachments visible on the gallery*"

So the files that you recieved (after you've enabled it) will be on ~/MyDocs, and otherwise on /home/user/.wazapp

Problem solved, both parties happy!

Edit: Can you also please consider a volume bar to change the loudness of the message tones and the notification sounds for wazapp?

Edit2:
So I have a better solution:

What if we just move it totally to ~/MyDocs to keep the /home partition clean.

Save the files within ~/MyDocs/.wazapp
but if you enable the toggle (the one I mentioned beforfe), Wazapp will rename the folder to /MyDocs/wazapp. This way, all the files that youve received will be visible on the gallery.

So you can easy show/hide the files within the gallery AND it wont fill the /home partition too!