Looking very good!
Unless you have already done so, now is the time to decide on and build the support units that will be added to your first batch of Corps in '43. An Inf Corps really costs 16 AP (more if you have to build the Divisions), not 10. The SU need to gain experience and at 1 pt/turn it takes a while. As to which type(s), you can't go wrong with Sappers (sounds like a mildly annoying Coca-Cola slogan) since it's very different from the current battles to attack dug-in Germans that are supported by reserves. So 100 (at least) Sapper Regiments formed by South Ural MD that should sit there and train.
A sprinkling of Hv Tank Reg is possible (and the only way to get the heavies to leave the pool), but these are not available to be formed until 10/42. A handful of Flame Tank Bat to get those out of the pool as well, but the production is rather low. You don't want a half strength SU occupying a slot that could contain a full strength Sapper Reg. I don't like the regular Tank SU due to the vehicle requirements, but it's a matter of taste as well.
I would think that saper is even less happy with the Air War than you - the Axis numbers are decreasing and you outproduce him.
Thanks for the advice gingerbread. I have already started building the support units. But I screwed up and started building them in STAVKA. Now if I try to build new ones in a MD(my own preference was the one near Saratov) it wants to pull them from STAVKA rather than build new ones. Is there a fix for this? I currently have about 60 Sapper regiments, 10 independent tank battalions, a half dozen or so AT regiments (are they worth it?), a flame tank battalion, and a few AA regiments. My plan was to build another 40 Sapper regiments and 20 or so HV Tank regiments when they become available. I'll follow your advice and build a few more flame tank battalions as well.
My main issues at the moment are that I ended my turn with only 84 APs and my Armaments are below 10,000. The reason for the low APs is that I spent 46 this turn forming 2 more Guards Rifle Corps. I would rather have avoided this, but it was necessary if I was to have any chance at all to free my trapped guards divisions. Although the attempt ultimately failed (well probably failed anyway as I believe Saper will retrap them) these 2 corps were instrumental in causing the retreat/rout of 6 panzer/motorized divisions.