In general, I agree with you completely. By the changes in facial structure and body build, it safe to assume it had been several years since he left village, but the way he left... You know there's still going to be hard feelings. I agree that wasn't the best choice in places to go. On the other hand, I don't know how sparse the villages are and how many choices Murang had. If Arth was vomiting blood, there was definitely some urgency, but... It's one of the things I don't like about this story. They don't explain much.
I started thinking it would have been better to make camp anywhere else in the wilderness than go to THAT village, but then I started thinking about some of the monsters they have run across. At that point I could understand needing a location with more eyes and weapons, but yeah, couldn't it have been ANYPLACE other than that village. But honestly, this is not a character fault, this is an author's failure. If an author is going to make a character make a decision this stupid, they need to be responsible to explain it to the reader. It needs to be made obvious the character is making a stupid decision (revealing more of the character) or you need to explain why they had no other choice. Since we didn't get a chance to hear the Mutant talking to himself and don't know any of the thought process behind his decision, we have no idea why he did it, so I am going to let Murang off the hook on this one can chalk it up to the author dropping the ball. This kind of stupidity just doesn't seem to suit his character as it's been revealed so far.
Regarding him going back, I respect Murang's decision, and I'm again annoyed with the author. Murang was butting heads with the authorities regarding his dragon riding, but we never got to see who raised him. Someone took in this orphan, and evidently instilled in him certain values. Who was that?
As to his thinking too small for his big dream, I kind of disagree here. His grand dream is to become Ruler of the Sky (whatever that is), but he's also decided he is not going to give up his own personal values to get there. Not everyone who disagrees with you is an enemy, and even if they are, they are still people. He cares about the people and is willing to make personal sacrifices to do what's right, and - honestly - that's not a bad reputation for a ruler to have.
(Spoilers)
I'm starting to get annoyed with Murang's character. He just left the village he barely escaped from with his life and then he wants to go back? In the first place, it was such a bad idea (even if his companion needed rest). With all the bad blood there, any other village would have been better. This situation is almost alluding to the fact that he would never be cut out to be an official rider(despite his skills). I mean, if a quest is accepted, is it professional to make so many unnecessary 'pit stops'?
If a huge lump of sh*t hits the fan, I wouldn't even care anymore because it all could have been prevented in some way or the other... -.- Besides, helping a bunch of people who could turn around and kill him in a heartbeat doesn't seem to be the way to get people to know him (seeing as he is hardly even known outside of that village). He thinks too small for the big dream he has.