What are the origin of the brachot following the haftara, and what are their halachic status? Are they personal to the leyner or is there an issue of being motzi the tzibbur etc? Is there any chiyuv involved?

The Brachot of the Haftara are a decree of Chachamim that the reader of the Haftara must say. He is not Motzi the listeners and therefore they may answer Baruch Hu Uvaruch Shmo. Rabbi Yitzchak Grinblat