Namekians don't have dicks. Only those of the Dragon Clan can reproduce, and while King Piccolo was a member of that clan, when he birthed Piccolo Jr., he opted to create a Warrior rather than a Dragon. As a result, Piccolo is built purely for combat, but can never have children.
His Nail part is probably happy just training and spending time with Dende. Kami is probably glad that he gets to still guard Earth without having to have the full responsibilities of being God.
Piccolo is probably conflicted over having his reason for existing made null and having merged with two people for ultimately pointless reasons. He probably just trains autistically while waiting for everyone he knows to die of old age.
Yes and like the song says, he's more human than the humans
>he forgot to meet his recommended amount of micronutrients