t3hwx9

Android compatibility layer is directly related to the specific device hardware adaptation. It's locked not only because it's proprietary (and partly licensed from another vendor), it has to be developed and tested first. Regarding predictive text input and MS Exchange support, it's complicated due to licensing conditions of those components. Jolla can provide access to it as a part of Sailfish X service (bundled with support and such), but not resell to end users.

Yes. It's a generic ubuntu 18.04 image apart from low-level integration into sailfish (or lack of) like host system sound mixer / power manager and input methods. Available gcc version is 8.3.0.

Pre-made rubber dust cover should be enough.

Oh, the long-awaited sequel to

It's pretty hard to fail worse than Microsoft Kin.