Yes, those buttons could be better located, and it'd be nice to have a dedicated focus button independent of the shutter release, especially with the tight grouping of the auto focus sensors.
These things are the subject of 1000's of posts, and there are work arounds. Do a search and see what others are doing: I am using the AE-AF button as my focus button so I can focus and recompose and for other reasons - I use the Auto - ISO function sometimes (but have to use the ISO button and command dial to "cycle" this off and on) - at times I re-program the depth of field button (on front of camera) or the function button (also on front) to do things I find awkward with the ISO and WB buttons (do a search to see how - or wade thru the manual - it's online).
You can save all this to U1 or U2, which is a wonderfully useful feature. As an example, I have U1 set to my flash settings with my "dumb down" focus settings so I can pass the camera to a person unfamiliar with D600 or use of separate focus buttons, and U2 is set for sunsets (I shoot lots of these). I use aperture priority and either manually set ISO or use Auto-ISO for most daylight shooting or interiors, manually setting WB at times depending on the light source(s).
I usually use the AF-C & single point with release "modes" and regardless of all these little work around problems think this the best camera I have owned or used, especially for my purposes. YMMV