Short answers, pulled from the story.
Scholars connect the name Bragi to the Old Norse noun bragr, which carries meanings of poetry and nobility. The Proto-Indo-European root *b'ragh-o links to forming things by religiously correct methods. This dual definition creates uncertainty about what the divine name originally signified.
Most scholars believe the god emerged through posthumous mythologization of the 9th-century skald Bragi Boddason. He served Swedish kings Ragnar Lodbrok, Osten Beli, and Bjorn at Hauge during the first half of that century. His Ragnarsdrape poem described images on a shield given by Ragnar including Thor fishing for Jormungandr.
Margaret Clunies Ross suggests his apotheosis occurred in the late tenth century before Christianity arrived. Eugen Mogk thought it happened as early as the late ninth century shortly after death. Heinz Klingenberg notes Bragi appears securely only in post-pagan sources.
Snorri Sturluson lists Bragi as husband of Iðunn and first maker of poetry in Skáldskaparmál. One stanza from Grettis saga portrays him again as Iðunn's husband. The ambiguity remains whether these passages refer to the god or the historical poet.
Lokasenna shows him exchanging insults with Loki at Aegir's feast. Iðunn defends him when Loki taunts his lack of martial prowess. Jan de Vries interprets this intervention as curbing Loki's verbal hostility to reflect regulated life-affirming speech functions.