Unfortunately It’s not possible to have both sequential and parallel tasks in the same project. As a workaround you could use negative filtering by tag to filter-out blocked actions.
You can create as many tags as you want. The only limit is on Areas.
More info on encryption here https://help.everdo.net/docs/sync/ess/#q-which-parts-of-the-data-get-encrypted-and-how
It’s not possible for staff to read you notes / tasks and the encryption key is never sent to the server.
In short, no, please see Add image/file to item, Attachements
This is planned, but not implemented yet. As you have noticed, the contexts do show up in the Desktop and the iOS apps, so they should also be added in the Android app for consistency.
The license is per user, so you can install on as many devices as you need.
You are welcome. You might find it helpful to review the documentation in order to learn more about the primary features.