Uh, why is MC accused of being stupid, or not having common sense? Is it stupid to start with low-level tasks? Just because you're strong enough to work construction doesn't mean you're a master architect. He's in no rush, so why not get a feel for guild work by doing simple, safe tasks?
Also, his thoughts about the boars shows he's pretty smart. He knows they'll destroy the town. He knows he can't destroy the forest. He's knows they're chasing something. He knows if he fires AOE-spells someone could get hurt.
You have to realise his 'common', is not actually common. He was very uncommon in his previous lives, and even moreso now. What is 'common' for him, is 'legendary' for most people. So, no he doesn't have 'common' sense.