I don't know if this fit in the description but Invicible saint salaryman is kinda go with the flow kind of dude.. not really op mc but he has chill and lax personality.. i kinda like how he is overshadow by the opness of people around him
Lir fir - So What If It’s an RPG World? Q: why? A: Self proclaimed as the one who has the most common sense among his circle
10 nen goshi no HikiNEET o Yamete Gaishutsushitara Jitaku goto Isekai ni Ten’ishiteta Q: Why? A: Yuuji either had a "light" head or he just don't really care. Anyway Kotarou "seems" to be the real "Hero" of the story. She's a dog though.
i immediately think of Death March. Wat is plot? Can u eat it? Satou probably could cook it and make it edible.
Gl with that one I might pick it up again it's really hard to read since there's too much pinyin. The other thing is the personality of the Mc. A bit of a spoiler it's the way he treats the time bomb(sentient) he has inside him. You'll understand when you read it.
For a less loli filled Death March (but with 18+ content but not explicit) http://www.novelupdates.com/series/slave-harem-in-the-labyrinth-of-the-other-world/ MC doesn't want to get in trouble so goes out of his way to be passive and mysterious. Very analytical and likes to experiment, but very low key in social situations. I don't know if that meets your criteria for easy going MC.
http://www.novelupdates.com/series/only-sense-online/ The MC here is very chill, he doesn't play the game to become the strongest, reminds me a lot of ryouma from the man picked by the gods
King's Avatar. Many people try to pick on the MC, but he always deals with them in a very calm and mature manner while effortlessly putting them in their place. Honestly, I can't think of anyone that handles challengers as perfectly and maturely as he does. He's very laid back in his day to day actions too.
I would add Magi Craft Meister to the list. Mc is pretty chill but cares about and helps the people he meets (mostly girls obviously...) has a slow release though.