most ever awning on a pole barn or steel building, is done much the same way,
one could always pour a concrete column in the earth, and bolt a pipe/tube on it to support the awning
If your planning on heating the floor one should put a thermo break (insulation board) between the floor and the out side any way,
and many around here use a trencher to make a "stem wall" when pouring a slab like that, kinda of a cross between a stem wall footer system and a floating slab,
in our country very little water will come up from under the building, thus there is nothing to freeze in the soil to make it expand, if you go under a building it is very dry and dusty, and or if you up a slab if there is a edge at all, it is dry,
some also depends on your soils, if there expansive, and if they are it could be good to dig down and remove and bring in some type of fill that is not expansive,
the fiber mesh does not replace wire or rebar, but IMO makes a better floor, and when welding or cutting less popping of the slab occurs,
you still need to run your rebar, (never was big believer in the wire) besides making it much harder take up a slab if it needs replaced, out side I think wire if placed correctly is good, but one gets it placed properly so seldom, most of the time it is on the bottom of the slab 1/2 in the grade and just on he bottom of the concrete most of the time.
If your jack hammering concrete out, the fiber offers very little restance to the process of breaking up the slab,
I would pour 6" in the drive way areas at least, on the edges where the benches and storage is 4 is fine,
I would ring the slab with rebar,1/2" at lest one if not two, and lap the ends, if some thing does crack it will not move away, as easily.
concrete by it nature will basically crack about ever 10-12 foot so cut joints or grove it to have straight cracks. try to not have cold joints where there is a large time lag between trucks and the concrete starts to set before the other truck gets there, if a know time is a have to one could be wise to set a tempory form board and make it nice and straight and when the other truck gets there pull it and continue at least the break will be straight if it does break at the meeting of the two loads
if possible try not to have sharp in side corners like around a pillar or footer, if you have to have a control joint in line with the footer/pillar.
my two cents