I believe there's a 50% accuracy penalty for firing on the move for the majority of units. Iirc Shermans have a better one and Panthers worse.
The rule (which gets constantly broken as Relic's patches do not value consistency) is tanks have 0.5 moving accuracy. USF's tanks, because of their advanced suspension, get 0.75 as a faction trait.
You can get the Panther's moving accuracy penalty down to zero by learning to time shots though: hit Stop just before it fires and it'll attack with full accuracy.
Bullshit. The game design has the Panther as a chaser unit. That means it needs accuracy.
Your history argument is invalid since we have SU-85s outranging Panthers (which they couldnt) due to its role in the game. So give Panthers the accuracy.
I really think buffing accuracy is the wrong approach. Even if you made them hit every shot they'd still have a hard time against heavy tanks, which they're meant to be a cost-effective counter to.
It should outperform the Tiger as a heavy killer, either by bringing the Tiger down or pushing the Panther up.