There is no such thing as a general "audiophile" music setting, there is just a "high fidelity (as much as possible)" setting. For the EQ alone that means using it to reduce the height/depth of peaks and dips in the headphone's or a speaker's in-room/cabin response. At best the closest to some idea of an "audiophile" setting is to smoothen out the peaks and dips first but then the overall result would be to have everything above, say, 2500hz or 4000hz softer than everything else. Either way, this will depend on what headphone you are using, which is why you can save several settings. I have two on my Note3 now - one for my ASG-1.3 (which I use on the go) and one for my HD600 (when the Note3 is docked into my home system). My EQ settings just smoothened out the response on both, but it will not necessarily benefit what you have. So first off when it comes to EQ - what headphones are you using?
Similarly you need to understand what those individual settings are for. EQ type refers to how the gain will affect the frequencies, ie peak has a more literal "center freq" that gets the full boost or cut but depending on the width or "Q" value it can affect several or a fraction of an octave higher and lower. High/low shelf puts a flat boost or cut above/below the "center" freq and then the Q affects how far below/above that is affected and by how much.
The next is Crossfeed, but this is basically just to deal with the inherent problem that headphones aren't speakers. In the latter both of your ears can hear both speakers including the (hopefully just the necessary) reflections, which helps with positional audio. This is not possible with headphones for obvious physical differences but Crossfeed simulates this by filtering a given range of frequencies above the selected crossover point across both channels. The higher you set the gain the louder the cross-filtration, the lower you set the center frequency the more frequencies get filtered across both channels. This partially depends on the headphone but not simply on whether it needs it more or not as the headphones that really need it will not really benefit from it, because there's a trade off: you trade a seemingly wider soundstage and end up with a deeper soundstage. So while the cymbals move closer to the center, vocals move forward and every thing else moves back, the more frequencies are affected the narrower the entire soundstage gets. Set it too high and the cymbals move to the center as to proportional size of the drum set, but the toms or even the snare might stay where they are. And on headphones that have really bad relative positioning, like Grados (cymbals next to your ears, no depth apart from forward vocals but all drums are forward anyway, etc) everything just narrows with barely any benefit to soundstage depth; on headphones like the HD800 for example the imaging gets even more precise, proportional to the size of the entire soundstage anyway.
Apart from that everything else has to do with connectivity (ie which USB driver to use, or streaming, etc), safety or some other way of dealing with gain (auto gain leveling, ReplayGain, etc), and then functionality.
