That he gets himself instantly into trouble makes the plot look kinda...
Well on the other hand, he should have just used the poison mist, why make more troubles?
This series jumps around too much. It feels like a chapter was skipped here, and it's happened before, too. If it didn't jump around like this, it would be a top-tier series.
I am guessing this is likely how he went about doing things in his old world. A travelling mage helping where he could whilst getting stronger as he did so.
Explains why people cheered when they saw him in his past life.