I literally numbered my post to fit yours.
1) "King isn´t even fucking trying", he has been shown to try, with sword, with full Zoan form. And i gave King probs for cutting off Marco´s wing, and Marco then counterattacked. Marco never tried to fight either of them 1vs1, his aim is to take attacks and keep them busy. So the claim "King is not even trying" is wrong, he has tried, Marco did not go down. And the claim "Marco has not done anything to King" is irrelevant since that was never the aim, factually and canonically.
2) Yes i know them, i know Marco attacking King in one scene after getting attacked himself, while keeping Queen busy, and winning that exchange, i know Marco taking tons of lasers and bullets from Queen, i know Marco was in the battlefield against King and gifters while healing Samurai and King following him and attacking in full Zoan mode, i know Queen dying of frustration that Marco won´t fall down and so forth. Marco never tried to fight King 1vs1, King has been trying, Marco was not interested since his aim is to keep the battlefield safe from the two. Now two people appeared that can fight King and Queen respectively, hence his role is over.