While I don't agree with the exact points OP gave, I do agree that soviets seem to be over performing a bit, especially in larger team games.
Particularly, the self-spotting mortars thanks to flairs and penals seem to be the main issues I can think of. The former seems out of place, since indirect fire shouldn't be able to self spot, and the later seems to be entirely due to the early scaling of penals.
Once a soviet player gets two Vet 1 mortars, they are basically impossible to counter, since they can constantly self spot - it also makes getting your own mortars incredibly challenging, which means ost has basically no structure clearing abilities, save for the weaker flamer-pios.
As for penals, the main problem is that their vet 0/1 performance is far too high, meaning late-game losses aren't too much of a problem. I think their Vet 2/3 performance should stay about the same, as well as cost, but their current performance vs. vet 3 grens at medium range is just far too high at vet 0/1, trivializing late game engagements. An alternative to a direct debuff to this unit would be increasing its pop-cap, meaning that supporting 4+ squads as well as other units would become much harder.
An argument could also be made the the PTRS upgrade doesn't seem like a 'trade' in terms of AT vs. AI, but just an overall upgrade. IMO it should work more like the shrek upgrade for PGrens, where AI power is dramatically reduced for AT power.
Excuse me, sir!!! But, I have no, even a single idea of what you are talking about!!! I don't even know that there is anyone on earth will even consider that any allies faction is more overperforming than the German faction in team game in general.
As a player who used to be ranked top ten in 4v4(allies mainly, axis top 50(during the allies op patch period just a few months ago), I refuse to keep playing axis because it is too boring.). Let me introduce you how ridiculous this game mode is.
1st. I have never played any game(regardless TBS, RTS, or FPS) that has any faction that will guarantee to win if the game past 25 or 30 mins. In this game, I achieve the dream. The only strategy I have and the only one I need to have to play axis is to hold my line for 25 mins. After that period, regardless of how good my opponents performed, my team will always turn the game around and win the game.
2nd. The ridiculous resources flow of axis factions compares to allies. If you have ever watched any replay, you will just realize how much more resources the axis have compared to the allies after the army is completely built up. I am talking about 500 more MP, 200 more Ammo, and 100 more Fuel.
3rd. The stupid strategy of completely lock down a part of the territory. Try this, one JT or elephant, plus 3 bunkers. Blame yourself if your opponents actually break through your line.
If you ever consider any allies support weapons or infantries squad are better than the Germans' in the first period of a game, especially 5~20 mins, please do me a favor and understand it. It is the only period that allies could win a game. Besides that period, there is hardly any chance for them to win a game.