my translation: Bushi 武士 existed in Japan from 10th to 19th centuries * * * the term 武士 first appeared in mid-Heian period 平安中期（10世紀）. Warriors before that might be [called] 武官, but definitely not 武士.
(ii) "「サムライ」は16世紀になって登場した比較的新しい語形であり、鎌倉時代から室町時代にかけては「サブライ」、平安時代には「サブラヒ」とそれぞれ発音されていた" ja.wikipedia.org for 侍
my translation: The pronunciation first appeared the 16th century. [Prior to that] from Kamakura period to [the following] Muromachi period, it was Saburai, whereas in Heian period [right before Kamakura period], Saburahi. [All for the same kanji 侍.)
(b) "Kanna HIMIYA 緋宮 栞那 — a dietitian, author and expert on samurai banquets whose ancestors were chefs to the Maeda clan of Ishikawa Prefecture in central Japan"