Short answers, pulled from the story.
Geri means roughly "the greedy one" or "the ravenous one," tracing back to the Proto-Germanic adjective geraz. Freki means "the insatiable one" or "glutton," from the Proto-Germanic frekaz, related to Old High German and Gothic words for covetous and desirous.
According to the Poetic Edda poem Grímnismál, Odin himself requires no food and lives on wine alone. He gives everything on his table to his two wolves, Geri and Freki.
They appear in the Poetic Edda poems Grímnismál and Helgakviða Hundingsbana I, in the Prose Edda books Gylfaginning and Skáldskaparmál written by Snorri Sturluson in the 13th century, and in skaldic poetry by Þjóðólfr of Hvinir, Egill Skallagrímsson, Þórðr Kolbeinsson, Einarr Skúlason, and Þórðr Sjáreksson.
Historian Michael Speidel links the wolves to archaeological evidence of wolf-pelt-wearing warriors and the frequency of wolf-related names among Germanic peoples. He argues this points to a pan-Germanic wolf-warrior cult centered on Odin, represented by groups such as the Úlfhéðnar, that declined after Christianization.
Yes. Jacob Grimm compared them to the wolf sacred to the Greek Apollo. Maurice Bloomfield connected them to the two dogs of Yama in Vedic mythology. Michael Speidel also found parallels in the Vedic Rudra and the Roman Mars, suggesting a shared Indo-European tradition of divine wolf companions.
Freki is also a name given to the monstrous wolf Fenrir in the Poetic Edda poem Völuspá. Folklorist John Lindow noted the irony that Odin feeds one Freki at his table each evening while being fated to be devoured by another Freki, Fenrir, at Ragnarök.