[CMMLD]

I am looking to add Bluetooth, Nav and Ipod to my 2007 E92 335i with professional HU and Logic 7. From all the posts in this forum, it has become clear that replacing any one part of the audio system (HU, Amp or Speakers) require specialized interfaces. My question to the group is this:

If I disconnect the factory HU, add aftermarket all-in-on Nav unit, install aftermarket amps and use the factory speakers (for the time being) will I create a situation where something will stop working, or produce tons of errors? To further qualify, I have no factory alarm either.

My concern at this point is also how to add a fibre optic block to complete the loop if the radio has been removed. I also don't see much in the way of how-to's for adding the steering wheel interface

I know this is a large number of questions, but I don't want to turn my car into a long term care project. Any and all advice is appreciated on this.