Can somebody elaborate on the input and output controls?
1. Is there a quick way to change both without the remote?
2. When using the remote, do you have to cycle through all the options?
3. And finally, are the volume controls independent per output or shared?
As a general comment, you can download the manual to get a full description of how the controls work. Not the best manual I've ever seen (that distinction probably belongs to RME), but it gets the job done. To answer your specific questions:
1. You can cycle through inputs (USB-COAX-OPT) by pressing the volume knob. Similarly, you cycle through outputs (Headphone-RCA-XLR-RCA+XLR) by
double-pressing the volume knob. A long press on the volume knob puts the unit in standby mode. Not exactly intuitive, but it gets the job done. Annoyingly, the unit does not automatically switch to headphone output when headphones are plugged in; my other DACs (RME, Benchmark) can be set to do this.
2. For changing inputs, it is as DoD says. For outputs, there are separate buttons on the remote for Headphones and Line Outs. To cycle between the three line out options, you must press the Line Out button repeatedly.
3. Volume settings are independent for headphones and line out. The RCA and XLR line outs share a common volume setting, which strikes me as a bit odd given that they can be switched on and off independently. I can imagine a use case where you'd want a volume-attenuated signal over one and a line-level signal over the other (e.g., running active monitors connected to XLR, using the EX5 as a preamp, while also running a line-level signal to an outboard headphone amp connected to RCA). I guess doing so would over-complicate the user interface.