You can start from the chapter where the anime season 2 ended. Usually, you can find this information on manga forums or from fellow fans' discussions.
The Mushoku Tensei anime's ending doesn't have a direct equivalent in the manga. The manga has a much broader and ongoing narrative that extends beyond where the anime concludes. There are still many exciting chapters in the manga that weren't covered in the anime.
Well, pinpointing exactly where the Mushoku Tensei anime ends in the manga can be a bit tricky. It varies depending on the pacing and story choices made during the anime adaptation. Sometimes scenes might be reordered or condensed.
Hard to say. It could be on hiatus, but without concrete information, it's difficult to give a definite answer. Try following the mangaka's social media or the manga's official website for the latest.