I can answer that, basically because guns are more effective against humans than magic unless you can cast immense spells. The reason is the same as our history of the crossbow. Before the crossbow you needed to be a well trained archer to be able to hit someone with an arrow, after the crossbow...
It's more that he was mad that these hermits were pulling him around like a dog on a leash. He has grown to be a very free spirited person who more than anything values his freedom to pick what he does and how he does it. Sometimes that involves him going with the flow, but he picks to go along...
I think the egg eating is supposed to be less weird in their world. If you consider WE eat chicken eggs, why not eat harpy eggs? Because he can talk to them? Doesn't that make it kinda better? Idk, it would probably be weird from MC's point of view, but it's not all that weird.
My man is going to have to start finishing all the marriages and working on a schedule to start impregnating all his wives/concubines LOL. Going to have a dozen wives at this rate.