At the start he said someone had came to steal from him so he killed him and something along the way of 'what's killing another trash we're not even considered human cause we're weak or sth like that' then he had learned that he was someone's "pet" or brother or sth so he had tried to fled or sth
Or at least that's what I remember...
Yes, you're right. I Just read the 1st chapter again, he does kill a guy who's someone's brother/pet bc he tried to steal from him;
Maybe the issue with him hesitating was bc he was in a group? He knew there were people that cared about them? Unlike the thief guy who he tought was just some trash like him? Idk
I choose to believe that that just shows the MC is a complex character
I have hopes that maybe the story and characters will be more complex; the old man is a very interesting and complex character by the looks of It and the world itself seems to be aswell so I hope the story keeps that up

Wasn't he sent to the mines cause he killed someone... how and why tf did he hesitate to kill someone who was about to kill him in the middle of a fight
That just makes no sense
There are so many small things that have been annoying me throughout this story idk if I can keep ignoring them for too long I hope the story and characters take a more serious turn and we get a proper story not just a goofy one that you have to turn your brain off to enjoy