1- If they are OP, why is it that the performance across automatch, both in high ranking and average across the board and during tournaments is poor.
2- IF the whole answer revolves around OH META, then wouldn't that mean that UKF/USF/OH are OP or stronger as the former 2 factions can deal with OH?
List of soviet nerfs
List of compensations
Now i'll reply adding teamgames into consideration.
I think what you try to address doesn't solve the discrepancy between 1v1, teamgames and inherent Soviet design problem.
I'll argue that Soviets for 2v2 and up is fine, as the game plays differently and there's a higher chance to make it into the late game. Most weakness are mitigated by the gamemode or complementary faction.
Regarding nerfs which would give room to buff other aspects, i only agree with 2 (Zis barrage, but not necessarily in that way + T70 power) and i'll add Ram needing a rework to be more interactive (problem is when combined with offmap). As for compensations i think you are just addressing superficial issues without dealing with core problems.
The nerfs to OH still miss AG based strats (or any T1 skip at all) and PG main problem is not their effectiveness in the mid to late game as to warrant vet 2/3 nerfs. If you revert their timing change then you basically made them have the same problems they had before (aka been mostly irrelevant). PG ties the gap in AI, specially when OH early muni is key.
FHT nerfs would be only because Soviets get access to T3 based units really late and they don't have the same flexibity to tech infantry AT without losing all AI (Penals) or having mp available to call Guards. I don't think the FHT is OP on the USF/UKF match ups.
In the same way OKW needs some early tech flexibity and healing, Soviets mp tech expenditure early on and T3 timing needs a look out, specially if you plan on nerfing the T70. Maybe take a look at M5 timing if T3 arrives earlier.