Updating as questions arise but for now this get's the hard questions out of the way
Cephalon Navis uses WFCD API to access a publicly accessible profile endpoint, which is used to request read-only data. In short this is data that you as a user can request from DE at any point.
The short answer, no. The long answer is Warframe Third-Party software and you.
https://www.warframe.com/gidNope not all, since you're not logging in.
For console players this is the only way to get your account ID in order to pull your data. No worries though, this still does not give Cephalon Navis write access to your account
For PC players simply use your EE.log in the root of
%LOCALAPPDATA%\Warframe
The arsenal feature will be temporarily disabled and reworked to be of a manual process
Oh sweet sol... you can email here