Sorry, anbox on Nexus 5.

Hi,
I would like to have some information, in particular

1. How are apps permissions handled against android?
2. Signal is not in the official store, but there is a project for Ubuntu Phone, is it possible to use that project now? https://github.com/janimo/textsecure-qml
3. Has anyone tested antox on Nexus 5?
4. Last question: Will the Ubports 15.04 version be compatible with the 16.04 currently in alpha phase?
   Thanx in advance