Yes the Bluetooth functions as you mentioned. On quedelix, parametric eq can be set from an app, so no dials. Balanced is balanced cable, to get full power from the quedelix- you likely don’t need this so don’t worry about it for now. I don’t see why not on the fosi for your use case. I hear the difference between amp/no amp- deeper bass, better separation and clarity. Some people don’t hear it and will not need the amp. I have the he400se and the difference is night and day for my ears. Can you test it out and return if it doesn’t doesn’t make a good difference? Happy Holidays!