Here is my opinion.
Golden Idol vs. Silver Freeze.
Golden Idol has a voodoo reflect which is very helpful in some cases. Silver Freeze can freeze multiple enemies, but that is useless against bosses like Darkhart since he dies quick, making it useless. The attack for Silver Freeze is better.
Seven Seas (?) Cutlass vs. Lost Sword of El Patron.
I think it's Seven Seas vs El Patron, has more attack than Corsair's. Anyways, Seven Seas has better boosts than El Patron. If you want to save skill points, Seven Seas is good. Attack-wise, El Patron only has a bit more, though it has a ghost form ability, and drain voodoo. It is good against voodo enemies, considering they are stronger and they (obviously) use voodoo.
Thunderspine Sword vs. Blade of the Abyss.
Blade of the Abyss has a unique inferno sweep ability, which isn't really all that helpful in terms of damage imo. Thunderspine has a shock sweep AND critical. Blade of the Abyss has a sort of critcal type ability, blood fire. So, it's kinda a close match.
IMO, Blade of the Abyss, El Patron, and Silver Freeze.