Lets attack these one by one.
1) SU-76 barrage is pretty much gone. This is good. Stug's, however, suck now. They are not as good as a PIV against infantry, and they royally suck against tanks, particularly because it is slow as hell. It should have had a cost increase, not a statistical nerf. Shrecks are NOT worth it, it takes 120 munis form an already starving army, and the soviets can get insane anti personnel units before you can get any shreks out. Drop a shrek (since they are doubles, this is very likely), and you risk giving the most potent infantry in the game AT capabilities.
2)Ostwinds are too expensive now, although admittedly, now they can hit something. The only reason why Stugs arent your first choice anymore is because, as stated, they arent as useful. I don't want my stug to kill infantry. I can get an ostwind for that.
3)Scout cars can be countered, but you have to be expecting it. In 1v1, it is not a big problem because there is a fuel sacrifice for it. However, the scout car as a support unit is supperior, in every respect that matters, to the armored car. It kills faster without troops in it. It can house snipers, conscripts or flamers. It can cap with any troops inside. For a cheaper cost.
Welcome to the Eastern Front, gentlemen. Now I understand the meaning of the achievement called "Delaying the Inevitable".
1. Not played loads with the StuG since the patch because I'm mostly running up against heavily infantry based soviets but when I've used it supported it's coped with much more expensive Russian tanks, it's dirt cheap in terms of manpower and T-34s have become more fuel-expensive (there's a 40mp disparity, the Stug has *way* better penetration). Obviously it's not as good as the more expensive/versatile P-IV vs. infantry but then it never has been. Not that Shrek drops aren't maybe a problem but guard PTRS and lmg drops are much more common.
2. Well, it used to be I'd have to get a StuG as my first tier 3 unit whatever the mix of the enemy's infantry and tanks because P-IVs were way more expensive and pretty lousy vs. armour, and Ostwinds used to just not do much damage. Both of those tanks are now in a decent place. Which means StuGs are now your AT/cheap option, Pz-IV's your flexible one and Ostwinds your infantry maulers. Which is what they're meant to be, really.
3. Yeah, in 2v2 and above I've no idea if the scout car is balanced. On 1v1 however, a really early flamecar will cripple the start of Soviet early game. If it comes out after the usual 3-scripts or whatever it's not that big a problem. The Ostheer armoured car could arguably use a small dps buff and an upgun cost decrease but it's quite useful for dealing with back-capping or upgunned at taking out scout cars, SU-76s, observation posts etc. etc. As noted elsewhere, while the German scout car is pretty much en route to whatever other techs you do, the Soviet one is basically deciding not to have weapons teams or ZiS guns without a costly back-tech.
I get that the Scout Car hasn't been nerfed (I never liked the Werfer, though, glad that's been mooted a bit) but other than that (I honestly don't see how big a deal the car itself is... maybe reduce accuracy from inside it a bit more or up the fuel by 5 or something...) I don't see what's so pro-Soviet about the patch. Yeah, StuGs aren't monsters any more, but they're also 120 mp cheaper and the other T-3 tanks are SO much better at doing their roles... i.e. barely more expensive than a T-34.