About Il2's and their durability, I have to second what Batz is saying...
I used them in AH to great success when operating with a group of Il2s using attacks coming from different directions at the same time.
In Forgotten Battles (as a reference point) if you setup a mission in QMB using any Il2 you want with just you in the flight, on the Crimean map with the airbase as the target- first pass, or second pass you are going to be SOL. I just tested this to be sure, There's 7 flaks total on the field, 3 near the 4 parked He111s on the left side from where you start out, and 3 closer to you between the runway and the taxi-way on the left side.
First pass I dove in, taking hits the entire way- destroyed 2 of the 3 flaks closest to me, and on my egress destroyed 3 of 3 flaks near the parked He111s. They got my oil though and I had holes throughout my wings and fuselage- 23mm on the right wing disabled.
Second pass, I line up on the truck convoy that has a flak in it, fire off my rockets. Then get hit, black smoke pouring from my engine and losing power at a steady rate.
This is about comparable with the defense 1 Flak will have in AH.
So I went back to the drawing board, got myself 2 wingmen and did the attack again. First pass I screwed up and only got 1 flak in each of the groups. I turned back, and finished off the rest of the flaks with my guns. One of my wingmen was missing, prolly shot down by the flaks. Second pass, finish off the remaining flaks and the single other AA half-track (dunno calibre, it spews yellow tracers though). Completely leveled the field without a scratch on me or my remaining wingman. Have the track if you wanna see it.
It shows nothing more, however, than the use of group/wing tactics to force the AA batteries to track multiple targets. This creates an ineffective defense, since they can't concentrate their fire on a single incoming plane.
Much like the Russians learned early on, after they lost almost the entire 4 ShAP equipped with the single seat Il2, employing group tactics and proper attack methods will the plane's full abilites be seen... otherwise, they will fall out of the skies like a swarm of mosquitos freshly sprayed with Raid.
It's not very fast, or manueverable, compared to other attack planes- so you have to use it in numbers.
-SW