Alright, had a little extra time to test those things.
Diamond Staff was considerably worse than Aqua Scepter, a weapon I didn't even bother ranking due to how heavily the Water Bolt outclassed it. It's got nice base damage but that's it. Water Bolt can hit the same enemy multiple times but Diamond Staff only hits once, on top of being slow and not very accurate. Would not recommend for anyone.
Starfury probably does deserve an entry since it cheeses the pirates pretty nicely with Magma Stone. Pirate's Curse isn't a problem as long as you leave enough space to walk backwards a bit. Extra points for being a melee weapon so it can activate Sharpened. Other than summoning weapons, I don't see any other pre-Hardmode weapon working well in this situation. (yes I tried Blood Rain Bow and it sucked)
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