A:AnswerHi Jo, Yes, you can hook up steering wheel controls. However, for more information about this, please refer to pg.39 of the link below. Thanks! ^Ron
https://www.sony.com/electronics/support/res/manuals/4697/b86fc6e795917dc1936ee6b2403ca164/46974182M.pdf
A:AnswerHello
No interference at all, just do not connect your phone if you do not want to use the feature however I am to understand you just want to add Sirius radio? This unit is meant to be a standalone head unit and if you are just wanting Sirius subscribe/purchase a add on screen from them , they do sell them. My other car is built in nav/radio and Sirius so no need for something like this .