Hashirama probably wins both scenarios.
Scenario 1 is abit iffy due to the boost of chakra sharing but scenario 2 is his definite win
Unlike full kurama Minatos kyuubi can only form 5 TBBs In a continuous barrage, not only that but each of full kyuubis TBB are larger and thus stronger than the TBBs that Minato can dish out
SS went through 12 PS-TBB and still eradicated PS, now there's only five of them with each being much weaker. Therefore resulting in Chojo kobetsu pummeling PS down to dirt and is still causing some damage to the kurama avatar
Without PS coating Mnatos TBB, the latters firepower is as good as nothing since SS can jus bich slap his TBB right back at him added with its own firepower that takes a dump on Minatos and he just like madara gets pasted
FTG is not cutting it when Minato is not evading hands that span multiple mountain ranges and that move as nearly as fast as a PS-TBB
And he is not winning the outlasting game due to the limit placed on his avatar.
And without his avatar he gets shat on by even base Hashirama