When the main group of adventures attacked a goblin village that was far bigger than they anticipated and saw many goblins run away into the direction of the worse ranked members of the adventurer guild that in no way had a chance (without ryouma of course) to win against that giant army, they didn't think to send at least one guy for example the teleporter mage to warn them? That's the stupidest thing that happened in this manga so far because it would have been sensible and more realistic if some adventurer showed up earlier and told them to run away and fortify the city or something then ryouma could have said don't worry I got this and his idea with the acid moat wouldn't have seemed as out of nowhere as it in my opinion did.
Also we are at the point of the story were not everybody would love him but most would start to fear him. It happened a little when the adventures saw the acid slimes for the first time but imagine even in a world were people can become comically strong a kid his age commanding an army of slimes and some of them can make any body disappear. Even if he appears to have a mature mind he started this goblin siege as an archer and showed his tactical genius as well as that he's more than capable to fight close range as well. Also his command of magic is superb so I would be terrified of this kid that could take on my hometown single handedly. Just because he's friendly now doesn't mean he will be forever and he is going to get stronger as he grows up.