Knuckle sucks, that´s true. It really shouldn´t matter if Youpi shows respect or whatever. He´s a man-eating monster! As long as that´s an unchanged fact, all ants HAVE TO DIE.

And while I, too, think it´s refreshing that not every shounen-arc has to end with a massive death toll, this anime is in dire need for more (significant) deaths. It´d cheapen all the tense build-up, if everyone comes out unscathed. Gon and Killua are probably plot-invincible, but other characters should die. Morel really should have, maybe to spur some true growth in Knuckle. Or have Knuckle die in front of his teacher´s eyes to provoke a reaction from him. Have Palm dead already, showing how futile and naive everybody´s rescue-plans were. Youpi, as I see it, is going to suicide-bomb himself to support the king against Netero. Pitou must die once Gon realizes that Kite cannot be brought back to life (I didn´t read the manga, I just strongly assume that Kite really is dead for good). Pouf will undoubtly die, because honestly he´s the most boring of the royal guard, both in personality and ability.

No idea about the king and Netero. Judging from Netero´s attitude and the king´s willingness to open up to those that impress him, I could see the both of them survive though this arc and become life-long friends, weird as that sounds.