The standard GUI has options for dealing with standard aircraft types. These are comparable to proprietary firmware - easy to use so long as what you want to do is in them. The advanced GUI doesn't have much in the way of preconfigured options, but allows you to do a lot more if you know what you want.
Quick summary: each channel gets a mixer, with a variety of types available. The most general form is the complex mixer, as the others are just subsets of it. It can include arbitrarily many mixes, which are processed in order. Each mix can have it's own source (stick inputs, switch values, or the output of any channel), curve, scale & offset, a switch (which can also be a channel) that enables or disables it, and a control for how it is combined with the output of the previous mixes. Details are in the manual. Beyond that, you need the tutorial you asked for.
If you search the forums, there are some general tutorials, plus tutorials explaining how various advanced mixes (like the sticky throttle hold) work. I wrote a
tutorial on setting up a Devo 10 for Phoenix
that shows how to use a switch to alternate between an aircraft and helicopter config in the same model, and provides fairly complete versions of each. It's a bit dated as the flight sim has had a number of updates since then, but the deviation information is still current.
